Index: django/core/management/commands/flush.py
===================================================================
--- django/core/management/commands/flush.py	(revision 7197)
+++ django/core/management/commands/flush.py	(working copy)
@@ -2,6 +2,11 @@
 from django.core.management.color import no_style
 from optparse import make_option
 
+try:
+    set
+except NameError:
+    from sets import Set as set   # Python 2.3 fallback
+
 class Command(NoArgsCommand):
     option_list = NoArgsCommand.option_list + (
         make_option('--verbosity', action='store', dest='verbosity', default='1',
@@ -61,7 +66,7 @@
             # Emit the post sync signal. This allows individual
             # applications to respond as if the database had been
             # sync'd from scratch.
-            emit_post_sync_signal(models.get_models(), verbosity, interactive)
+            emit_post_sync_signal(set(models.get_models()), verbosity, interactive)
 
             # Reinstall the initial_data fixture.
             from django.core.management import call_command