Blank pages after comment

Hey all,

For some reason I've been getting blank pages after posting comments on my ProjectPier installation.

I went through the forum looking for answers, and all I found was a suggestion to turn debug to true in the config file, so I did. This is what I found:

Fatal error: Call to undefined method ProjectFile::getViewUrl() in /home/user/public_html/pm/application/controllers/CommentController.class.php on line 94

Any ideas how to solve this problem?

Thanks.