Index: manipulators.py
===================================================================
--- manipulators.py	(revision 3946)
+++ manipulators.py	(working copy)
@@ -286,7 +286,7 @@
         # This is really not going to work for fields that have different
         # form fields, e.g. DateTime.
         # This validation needs to occur after html2python to be effective.
-        field_val = all_data.get(f.attname, None)
+        field_val = all_data.get(f.name, None)
         if field_val is None:
             # This will be caught by another validator, assuming the field
             # doesn't have blank=True.