Index: django/newforms/fields.py
===================================================================
--- django/newforms/fields.py	(revision 6142)
+++ django/newforms/fields.py	(working copy)
@@ -435,6 +435,9 @@
     def clean(self, value):
         "Returns a Python boolean object."
         super(BooleanField, self).clean(value)
+        # Check for '0' which is what as_hidden will give us for False
+        if value == '0':
+            return False
         return bool(value)
 
 class NullBooleanField(BooleanField):