Index: formsets.py
===================================================================
--- formsets.py	(revision 7378)
+++ formsets.py	(working copy)
@@ -53,7 +53,7 @@
             self._initial_form_count = 0
             self._total_form_count = self.extra
         initial = {TOTAL_FORM_COUNT: self._total_form_count, INITIAL_FORM_COUNT: self._initial_form_count}
-        self.management_form = ManagementForm(initial=initial, auto_id=auto_id, prefix=prefix)
+        self.management_form = ManagementForm(initial=initial, auto_id=auto_id, prefix=self.prefix)
 
         # instantiate all the forms and put them in self.forms
         self.forms = []