Index: fields.py
===================================================================
--- fields.py	(revision 5691)
+++ fields.py	(working copy)
@@ -382,7 +382,6 @@
 
     def clean(self, value):
         "Returns a Python boolean object."
-        super(BooleanField, self).clean(value)
         return bool(value)
 
 class NullBooleanField(BooleanField):