Index: manipulators.py
===================================================================
--- manipulators.py	(Revision 3518)
+++ manipulators.py	(Arbeitskopie)
@@ -109,7 +109,10 @@
         if self.change:
             self.fields_added, self.fields_changed, self.fields_deleted = [], [], []
             for f in self.opts.fields:
-                if not f.primary_key and str(getattr(self.original_object, f.attname)) != str(getattr(new_object, f.attname)):
+                if type(getattr(new_object, f.attname)) is bool:
+                    if not f.primary_key and getattr(self.original_object, f.attname) != getattr(new_object, f.attname):
+                        self.fields_changed.append(f.verbose_name)
+                elif not f.primary_key and str(getattr(self.original_object, f.attname)) != str(getattr(new_object, f.attname)):
                     self.fields_changed.append(f.verbose_name)
 
         # Save many-to-many objects. Example: Set sites for a poll.