Desp: Is this giving you errors here? If not, make sure you applied the changes in cp2_forums.cgi.
D-Talk: After freshly installing the hack, i was unable to duplicate the issue. The main parts I would recommend to recheck is the parts in ubb_newtopic.cgi, ubb_newreply.cgi and ubb_editpost.cgi. Those files are the ones that modify the approval file and append to it. (btw, is anyone else expierencing this issue?)
Now i did notice an issue with cp2_postapproval.pl as it was pming the author, a feature i have not yet totally installed. Please redownload the zip. The only changed file is cp2_postapproval.