Yeah, I told you about this fix.
When you add a moderator it finds all private forums and adds the moderator a custom permission through the use of an access mask. This is quite anoying when you have large complicated forum permissions and access masks as you have to go and undo the damage. Commenting out the line stops the custom moderator access to private forums being added, but still adds the moderator and gives them permission on the respective forum and child forums.
Just comment it out and see how much time it will save you
HTH.