It's becoming more obvious that you have not used all the files included with the phpBBport and overwrote your exisintg ones. If you used all the files with the phpBBport in the beginning, then the Private Messages should now be controlled by the Forums not Nuke.

The phpBBport came with modules that replace your exisiting ones. You can't just upload the Forum mopdule and expect everything to work. ALL needs uploaded.

edit: The setlocale error has been covered. You can search the Forums here and at http://www.nukecops.com and find the solution for that.

mikem