diff --git a/.gitignore b/.gitignore
index eef3882..c31d5c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@ pushreg
 pbackup
 mcmd.py
 dbconfig_local.py
+diffmanagement
 
 pip-log.txt
 build
diff --git a/pexp/dumpdata_test_correct_output.txt b/pexp/dumpdata_test_correct_output.txt
new file mode 100644
index 0000000..5a4e6ac
--- /dev/null
+++ b/pexp/dumpdata_test_correct_output.txt
@@ -0,0 +1,40 @@
+[
+    {
+        "pk": 1, 
+        "model": "pexp.project", 
+        "fields": {
+            "topic": "John's gathering", 
+            "polymorphic_ctype": 2
+        }
+    }, 
+    {
+        "pk": 2, 
+        "model": "pexp.project", 
+        "fields": {
+            "topic": "Sculpting with Tim", 
+            "polymorphic_ctype": 3
+        }
+    }, 
+    {
+        "pk": 3, 
+        "model": "pexp.project", 
+        "fields": {
+            "topic": "Swallow Aerodynamics", 
+            "polymorphic_ctype": 4
+        }
+    }, 
+    {
+        "pk": 2, 
+        "model": "pexp.artproject", 
+        "fields": {
+            "artist": "T. Turner"
+        }
+    }, 
+    {
+        "pk": 3, 
+        "model": "pexp.researchproject", 
+        "fields": {
+            "supervisor": "Dr. Winter"
+        }
+    }
+]
diff --git a/pexp/management/commands/pcmd.py b/pexp/management/commands/pcmd.py
index 58bdfa8..5a53db4 100644
--- a/pexp/management/commands/pcmd.py
+++ b/pexp/management/commands/pcmd.py
@@ -20,7 +20,7 @@ class Command(NoArgsCommand):
     help = ""
 
     def handle_noargs(self, **options):
-        print 'polycmd - sqlite test db is stored in:',settings.DATABASE_NAME
+        print 'polycmd - sqlite test db is stored in:',settings.SQLITE_DB_PATH
         print
 
         """
diff --git a/pexp/management/commands/polymorphic_create_test_data.py b/pexp/management/commands/polymorphic_create_test_data.py
index ff2fbd0..e45811c 100644
--- a/pexp/management/commands/polymorphic_create_test_data.py
+++ b/pexp/management/commands/polymorphic_create_test_data.py
@@ -20,7 +20,7 @@ class Command(NoArgsCommand):
     help = ""
 
     def handle_noargs(self, **options):
-        #print 'polycmd - sqlite test db is stored in:',settings.SQLITE_DB_PATH
+        print 'polycmd - sqlite test db is stored in:',settings.SQLITE_DB_PATH
         print
 
         Project.objects.all().delete()
diff --git a/polymorphic/base.py b/polymorphic/base.py
index 241b894..558bd29 100644
--- a/polymorphic/base.py
+++ b/polymorphic/base.py
@@ -3,6 +3,9 @@
     Please see README.rst or DOCS.rst or http://bserve.webhop.org/wiki/django_polymorphic
 """
 
+import sys
+import inspect
+
 from django.db import models
 from django.db.models.base import ModelBase
 
@@ -75,7 +78,7 @@ class PolymorphicModelBase(ModelBase):
     def get_inherited_managers(self, attrs):
         """
         Return list of all managers to be inherited/propagated from the base classes;
-        use correct mro, only use managers with _inherited==False,
+        use correct mro, only use managers with _inherited==False (they are of no use),
         skip managers that are overwritten by the user with same-named class attributes (in attrs)
         """
         add_managers = []; add_managers_keys = set()
@@ -150,3 +153,26 @@ class PolymorphicModelBase(ModelBase):
             raise AssertionError(e)
         return manager
 
+    # hack: a small patch to Django would be a better solution.
+    # Django's management command 'dumpdata' relies on non-polymorphic
+    # behaviour of the _default_manager. Therefore, we catch any access to _default_manager
+    # here and return the non-polymorphic default manager instead if we are called from 'dumpdata.py'
+    # (non-polymorphic default manager is 'base_objects' for polymorphic models).
+    # This way we don't need to patch django.core.management.commands.dumpdata
+    # for all supported Django versions.
+    # TODO: investigate Django how this can be avoided
+    _dumpdata_command_running = False
+    if len(sys.argv)>1: _dumpdata_command_running = ( sys.argv[1] == 'dumpdata' )
+    def __getattribute__(self, name):
+        if name=='_default_manager':
+            if self._dumpdata_command_running:
+                frm = inspect.stack()[1] # frm[1] is caller file name, frm[3] is caller function name
+                if 'django/core/management/commands/dumpdata.py' in frm[1]:
+                    return self.base_objects
+                #caller_mod_name = inspect.getmodule(frm[0]).__name__  # does not work with python 2.4
+                #if caller_mod_name == 'django.core.management.commands.dumpdata':
+
+        return super(PolymorphicModelBase, self).__getattribute__(name)
+
+
+
diff --git a/polymorphic/management/commands/polymorphic_dumpdata.py b/polymorphic/management/commands/polymorphic_dumpdata.py
index ca7e452..09cf477 100644
--- a/polymorphic/management/commands/polymorphic_dumpdata.py
+++ b/polymorphic/management/commands/polymorphic_dumpdata.py
@@ -1,19 +1,9 @@
 """
-polymorphic_dumpdata is just a slightly modified version
-of Django's dumpdata. In the long term, patching Django's
-dumpdata definitely is a better solution.
-
-Use the Django 1.1 or 1.2 variant of dumpdata, depending of the
-Django version used.
+polymorphic_dumpdata has been disabled since it's no longer needed
+(this is now handled by polymorphic.base.PolymorphicModelBase).
 """
 
-import django
-
-if django.VERSION[:2]==(1,1):
-    from polymorphic_dumpdata_11 import Command
-
-elif django.VERSION[:2]==(1,2):
-    from polymorphic_dumpdata_12 import Command
-
-else:
-    assert False, 'Django version not supported'
+assert False, """
+ERROR: The management command polymorphic_dumpdata is no longer supported or needed.
+       Please use the standard Django dumpdata management command instead!
+"""
diff --git a/polymorphic/management/commands/polymorphic_dumpdata_11.py b/polymorphic/management/commands/polymorphic_dumpdata_11.py
deleted file mode 100644
index bc8f47d..0000000
--- a/polymorphic/management/commands/polymorphic_dumpdata_11.py
+++ /dev/null
@@ -1,94 +0,0 @@
-
-from django.core.exceptions import ImproperlyConfigured
-from django.core.management.base import BaseCommand, CommandError
-from django.core import serializers
-from django.utils.datastructures import SortedDict
-
-from optparse import make_option
-
-class Command(BaseCommand):
-    option_list = BaseCommand.option_list + (
-        make_option('--format', default='json', dest='format',
-            help='Specifies the output serialization format for fixtures.'),
-        make_option('--indent', default=None, dest='indent', type='int',
-            help='Specifies the indent level to use when pretty-printing output'),
-        make_option('-e', '--exclude', dest='exclude',action='append', default=[],
-            help='App to exclude (use multiple --exclude to exclude multiple apps).'),
-    )
-    help = 'Output the contents of the database as a fixture of the given format.'
-    args = '[appname ...]'
-
-    def handle(self, *app_labels, **options):
-        from django.db.models import get_app, get_apps, get_models, get_model
-
-        format = options.get('format','json')
-        indent = options.get('indent',None)
-        exclude = options.get('exclude',[])
-        show_traceback = options.get('traceback', False)
-
-        excluded_apps = [get_app(app_label) for app_label in exclude]
-
-        if len(app_labels) == 0:
-            app_list = SortedDict([(app, None) for app in get_apps() if app not in excluded_apps])
-        else:
-            app_list = SortedDict()
-            for label in app_labels:
-                try:
-                    app_label, model_label = label.split('.')
-                    try:
-                        app = get_app(app_label)
-                    except ImproperlyConfigured:
-                        raise CommandError("Unknown application: %s" % app_label)
-
-                    model = get_model(app_label, model_label)
-                    if model is None:
-                        raise CommandError("Unknown model: %s.%s" % (app_label, model_label))
-
-                    if app in app_list.keys():
-                        if app_list[app] and model not in app_list[app]:
-                            app_list[app].append(model)
-                    else:
-                        app_list[app] = [model]
-                except ValueError:
-                    # This is just an app - no model qualifier
-                    app_label = label
-                    try:
-                        app = get_app(app_label)
-                    except ImproperlyConfigured:
-                        raise CommandError("Unknown application: %s" % app_label)
-                    app_list[app] = None
-
-        # Check that the serialization format exists; this is a shortcut to
-        # avoid collating all the objects and _then_ failing.
-        if format not in serializers.get_public_serializer_formats():
-            raise CommandError("Unknown serialization format: %s" % format)
-
-        try:
-            serializers.get_serializer(format)
-        except KeyError:
-            raise CommandError("Unknown serialization format: %s" % format)
-
-        objects = []
-        for app, model_list in app_list.items():
-            if model_list is None:
-                model_list = get_models(app)
-
-            for model in model_list:
-                if not model._meta.proxy:
-
-#### patch for django_polymorphic ######################################################
-                    # modified for django_polymorphic compatibility:
-                    # do not use polymorphic queryset for serialisation
-                    # (as the dumpdata/serializer implementation depends
-                    # on non-polymorphic behavious) 
-                    base_manager=model._default_manager
-                    if getattr(model,'polymorphic_model_marker',None) != None:
-                        base_manager=getattr(model,'base_objects',None)
-                    objects.extend(base_manager.all())
-
-        try:
-            return serializers.serialize(format, objects, indent=indent)
-        except Exception, e:
-            if show_traceback:
-                raise
-            raise CommandError("Unable to serialize database: %s" % e)
diff --git a/polymorphic/management/commands/polymorphic_dumpdata_12.py b/polymorphic/management/commands/polymorphic_dumpdata_12.py
deleted file mode 100644
index 03ab2fd..0000000
--- a/polymorphic/management/commands/polymorphic_dumpdata_12.py
+++ /dev/null
@@ -1,175 +0,0 @@
-from django.core.exceptions import ImproperlyConfigured
-from django.core.management.base import BaseCommand, CommandError
-from django.core import serializers
-from django.db import connections, DEFAULT_DB_ALIAS
-from django.utils.datastructures import SortedDict
-
-from optparse import make_option
-
-class Command(BaseCommand):
-    option_list = BaseCommand.option_list + (
-        make_option('--format', default='json', dest='format',
-            help='Specifies the output serialization format for fixtures.'),
-        make_option('--indent', default=None, dest='indent', type='int',
-            help='Specifies the indent level to use when pretty-printing output'),
-        make_option('--database', action='store', dest='database',
-            default=DEFAULT_DB_ALIAS, help='Nominates a specific database to load '
-                'fixtures into. Defaults to the "default" database.'),
-        make_option('-e', '--exclude', dest='exclude',action='append', default=[],
-            help='App to exclude (use multiple --exclude to exclude multiple apps).'),
-        make_option('-n', '--natural', action='store_true', dest='use_natural_keys', default=False,
-            help='Use natural keys if they are available.'),
-    )
-    help = 'Output the contents of the database as a fixture of the given format.'
-    args = '[appname ...]'
-
-    def handle(self, *app_labels, **options):
-        from django.db.models import get_app, get_apps, get_models, get_model
-
-        format = options.get('format','json')
-        indent = options.get('indent',None)
-        using = options.get('database', DEFAULT_DB_ALIAS)
-        connection = connections[using]
-        exclude = options.get('exclude',[])
-        show_traceback = options.get('traceback', False)
-        use_natural_keys = options.get('use_natural_keys', False)
-
-        excluded_apps = set(get_app(app_label) for app_label in exclude)
-
-        if len(app_labels) == 0:
-            app_list = SortedDict((app, None) for app in get_apps() if app not in excluded_apps)
-        else:
-            app_list = SortedDict()
-            for label in app_labels:
-                try:
-                    app_label, model_label = label.split('.')
-                    try:
-                        app = get_app(app_label)
-                    except ImproperlyConfigured:
-                        raise CommandError("Unknown application: %s" % app_label)
-
-                    model = get_model(app_label, model_label)
-                    if model is None:
-                        raise CommandError("Unknown model: %s.%s" % (app_label, model_label))
-
-                    if app in app_list.keys():
-                        if app_list[app] and model not in app_list[app]:
-                            app_list[app].append(model)
-                    else:
-                        app_list[app] = [model]
-                except ValueError:
-                    # This is just an app - no model qualifier
-                    app_label = label
-                    try:
-                        app = get_app(app_label)
-                    except ImproperlyConfigured:
-                        raise CommandError("Unknown application: %s" % app_label)
-                    app_list[app] = None
-
-        # Check that the serialization format exists; this is a shortcut to
-        # avoid collating all the objects and _then_ failing.
-        if format not in serializers.get_public_serializer_formats():
-            raise CommandError("Unknown serialization format: %s" % format)
-
-        try:
-            serializers.get_serializer(format)
-        except KeyError:
-            raise CommandError("Unknown serialization format: %s" % format)
-
-        # Now collate the objects to be serialized.
-        objects = []
-        for model in sort_dependencies(app_list.items()):
-            if not model._meta.proxy:
-
-#### patch for django_polymorphic ######################################################
-                # modified for django_polymorphic compatibility:
-                # do not use polymorphic queryset for serialisation
-                # (as the dumpdata/serializer implementation depends
-                # on non-polymorphic behavious) 
-                base_manager=model._default_manager
-                if getattr(model,'polymorphic_model_marker',None) != None:
-                    base_manager=getattr(model,'base_objects',None)
-                objects.extend(base_manager.using(using).all())
-
-        try:
-            return serializers.serialize(format, objects, indent=indent,
-                        use_natural_keys=use_natural_keys)
-        except Exception, e:
-            if show_traceback:
-                raise
-            raise CommandError("Unable to serialize database: %s" % e)
-
-def sort_dependencies(app_list):
-    """Sort a list of app,modellist pairs into a single list of models.
-
-    The single list of models is sorted so that any model with a natural key
-    is serialized before a normal model, and any model with a natural key
-    dependency has it's dependencies serialized first.
-    """
-    from django.db.models import get_model, get_models
-    # Process the list of models, and get the list of dependencies
-    model_dependencies = []
-    models = set()
-    for app, model_list in app_list:
-        if model_list is None:
-            model_list = get_models(app)
-
-        for model in model_list:
-            models.add(model)
-            # Add any explicitly defined dependencies
-            if hasattr(model, 'natural_key'):
-                deps = getattr(model.natural_key, 'dependencies', [])
-                if deps:
-                    deps = [get_model(*d.split('.')) for d in deps]
-            else:
-                deps = []
-
-            # Now add a dependency for any FK or M2M relation with
-            # a model that defines a natural key
-            for field in model._meta.fields:
-                if hasattr(field.rel, 'to'):
-                    rel_model = field.rel.to
-                    if hasattr(rel_model, 'natural_key'):
-                        deps.append(rel_model)
-            for field in model._meta.many_to_many:
-                rel_model = field.rel.to
-                if hasattr(rel_model, 'natural_key'):
-                    deps.append(rel_model)
-            model_dependencies.append((model, deps))
-
-    model_dependencies.reverse()
-    # Now sort the models to ensure that dependencies are met. This
-    # is done by repeatedly iterating over the input list of models.
-    # If all the dependencies of a given model are in the final list,
-    # that model is promoted to the end of the final list. This process
-    # continues until the input list is empty, or we do a full iteration
-    # over the input models without promoting a model to the final list.
-    # If we do a full iteration without a promotion, that means there are
-    # circular dependencies in the list.
-    model_list = []
-    while model_dependencies:
-        skipped = []
-        changed = False
-        while model_dependencies:
-            model, deps = model_dependencies.pop()
-
-            # If all of the models in the dependency list are either already
-            # on the final model list, or not on the original serialization list,
-            # then we've found another model with all it's dependencies satisfied.
-            found = True
-            for candidate in ((d not in models or d in model_list) for d in deps):
-                if not candidate:
-                    found = False
-            if found:
-                model_list.append(model)
-                changed = True
-            else:
-                skipped.append((model, deps))
-        if not changed:
-            raise CommandError("Can't resolve dependencies for %s in serialized app list." %
-                ', '.join('%s.%s' % (model._meta.app_label, model._meta.object_name)
-                for model, deps in sorted(skipped, key=lambda obj: obj[0].__name__))
-            )
-        model_dependencies = skipped
-
-    return model_list
\ No newline at end of file
diff --git a/polymorphic/showfields.py b/polymorphic/showfields.py
index 464f9eb..f297c10 100644
--- a/polymorphic/showfields.py
+++ b/polymorphic/showfields.py
@@ -27,7 +27,12 @@ class ShowFieldBase(object):
                 o = getattr(self, f.name)
 
                 if isinstance(f, (models.ForeignKey)):
-                    out += ': ' + ( '"None"' if o is None else '"' + o.__class__.__name__ + '"' )
+                    #out += ': ' + ( '"None"' if o is None else '"' + o.__class__.__name__ + '"' )
+                    out += ': '
+                    if o is None:
+                        out += '"None"'
+                    else:
+                        out += '"' + o.__class__.__name__ + '"'
 
                 elif isinstance(f, (models.ManyToManyField)):
                     out += ': %d' % o.count()
diff --git a/settings.py b/settings.py
index 2eafaa8..01e4ac4 100644
--- a/settings.py
+++ b/settings.py
@@ -21,12 +21,12 @@ if django.VERSION[:2][0]>=1 and django.VERSION[:2][1]>=3:
     DATABASES = {
         'default': {
             'ENGINE': 'django.db.backends.sqlite3',
-            'NAME': '/var/tmp/django-polymorphic-test-db.sqlite3'
+            'NAME': SQLITE_DB_PATH
         }
     }
 else:
     DATABASE_ENGINE = 'sqlite3'           # 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
-    DATABASE_NAME = '/var/tmp/django-polymorphic-test-db.sqlite3'             # Or path to database file if using sqlite3.
+    DATABASE_NAME = SQLITE_DB_PATH             # Or path to database file if using sqlite3.
     DATABASE_USER = ''             # Not used with sqlite3.
     DATABASE_PASSWORD = ''         # Not used with sqlite3.
     DATABASE_HOST = ''             # Set to empty string for localhost. Not used with sqlite3.
diff --git a/test_all_versions b/test_all_versions
index 4b09640..41d2ba9 100755
--- a/test_all_versions
+++ b/test_all_versions
@@ -21,8 +21,19 @@ function restore_django {
 }
 
 function test_python_version {
+    echo ; echo ; echo
+    echo "#########################################################################"
+    echo "### Testing Python $1, Django $2"
+    echo "#########################################################################"
+    echo
+
     if which python$1 ; then
-        if ! python$1 manage.py test ; then
+        if ! python$1 manage.py test polymorphic; then
+            echo ERROR
+            restore_django
+            exit 10
+        fi
+        if ! ./test_dumpdata $1 ; then
             echo ERROR
             restore_django
             exit 10
@@ -35,9 +46,9 @@ function test_python_version {
 }
 
 function test_all_python_versions {
-    test_python_version 2.4
-    test_python_version 2.5
-    test_python_version 2.6
+    test_python_version 2.4 $1
+    test_python_version 2.5 $1
+    test_python_version 2.6 $1
 }
 
 function test_django_version {
@@ -51,7 +62,7 @@ function test_django_version {
     rm -f django
     ln -s django-versions/django$1 django
     cd ..
-    test_all_python_versions
+    test_all_python_versions $1
 }
 
 test_django_version 1.1
diff --git a/test_dumpdata b/test_dumpdata
index 77da0e2..28b31a3 100755
--- a/test_dumpdata
+++ b/test_dumpdata
@@ -2,6 +2,7 @@
 
 rm -f /var/tmp/django-polymorphic-test-db.sqlite3
 rm -f /ram/django-polymorphic-test-db.sqlite3
+
 TMPFILE=/tmp/django-polymorphic-test.dump
 
 PYCMD="python$1"