I am an admin at my board and when i, or any of the mods attempt to move a topic we get a

FYI

Invalid input! One or more items submitted in the form are not in the proper format. » Please use your browser's back button to return.

This also happens when people try to delete more than one pm...i am guessing i need to edit the move_topic.cgi file but i was wondering if anyone could tell me exactly how to fix it.
Thanks

Sycho_2