I am getting a similar error. Had to turn off the photo albums temporary to get the forum back up. Running on vBulletin 4.1.3
Fatal error: Call to undefined function pp_get_filename() in /home/jrcbdcom/public_html/forum.php(653) : eval()'d code on line 186
The vBulletin folks said it was in this code. Not sure if that is true. Can you help?