Ok you guys, I have just discovered a minor error caused by this hack, hopefully one of you can tell me what I did wrong.

When you try to delete a pm this is what it comes up with:
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.
You can still enter the pm and delete it from there though.
TIA, kennyp