Brian

You are correct about the typo with $bbuserino variable. There's really no reason that should cause a problem though as the check to see if that variable is empty is really just more of a percaution and the foreach statement is still processing the proper variable.

For the permissions thing, it almost sounds like you've answered your own question. If a user is a member of two groups and one group has permissions for a category then they are going to be able to view that category. If you don't want that group to have permissions to a specific category then you need to change the permissions for that group in that specific category (as you said above).