First off, let me just say I appreciate the help that everyone has given me. If people can bear with me just a tad longer I'd appreciate it.
To update: I have configured the cookies in control panel to go to all of my domain (.slushfactory.com). Unfortunately, this hasn't resolved the problem.
To get back to the basics I am using the original loginfile.php file that RobAC included with his hack. I made two websites, my regular index (indextest.php) that also has a regular header and HTML code in it, and then a 2nd page (test.php) that only contains the INCLUDE file that calls to loginfile.php. I don't get the warning header error on the test.php page, but I still get it on the indextest.php one.
Full URLs:
http://www.slushfactory.com/indextest.php
http://www.slushfactory.com/test.php
Because the test.php works, it's obvious that the problem exists in my indextest.php page. However, I'm not sure where. The include file that calls to loginfile.php is after the header information and is someways down the page. The exact line I use is:
<?php
include("/home/slush/public_html/forum/loginfile.php");
?>
Aside from that, all the rest of the page is written in regular 'ol HTML. Could this be the problem? I assumed all I had to do was throw in the php include statement.
Am I missing something? I'm willing to post whatever code someone needs if they're willing to look at it.
Thanks,
Brian