To narrow things down, I disabled every plugin in my LocalSettings.php file and confirmed that Special:SpecialPages was working. I then enabled AuthWP.php and it stopped working.
As far as PHP errors are concerned, I followed the guidance found on http://www.mediawiki.org/wiki/Manual:How_to_debug#PHP_errors but it did not display any php errors whatsoever. I do not have access to try this in php.ini. I am kind of stuck because I am getting 0 PHP errors and I can't figure out what specifically is causing it except AuthWP.php being enabled.
I upgraded my wiki to 1.20.4 with only AuthWP.php enabled in my LocalSettings.php. I try to go to SpecialPages, it gives me a blank white page. I disable AuthWP.php and it works again.
This is a real head scratcher...I may try a fresh install with no content and only AuthWP.php. If it works, then I know something in my database is screwed up and I can just export to xml, nuke it and start over.
Thanks for the quick reply!