I was having problems with the exhibit plugin. Mostly because my server has:
[SCRIPT_NAME] => /cgi-system/php.cgi
which doesn’t work for when it is trying to determine the post.php. I changed it those to the variable mentioned above, which uses:
[SCRIPT_URL] => /wp-admin/post.php
and now with $_SERVER[‘SCRIPT_URL’] everything now works! woohoo!