fGallery Problem: Leaving Comments Causes 404

I was wondering if someone could help me diagnose my problem. I’m using fGallery and every time someone leaves a comment they get a 404 Error page saying that the page doesn’t exist. I know fundamentally what’s happening, but I’m not sure how to diagnose it. The script uses

<form action="$PHP_SELF" method="post">.

From what I’ve read, $PHP_SELF has been deprecated and it should be $_SERVER['PHP_SELF'], instead, so I changed it and no dice. If I use this variable, the page reloads back to the Gallery Overview page.

If I set < form action="" method="post"> (to see if I can make the script run as the default) it also gives me a 404 but posts the comment to the database.

I’ve tried about every iteration of having the script read to itself I could think of. I could use some help.