What forum script are you using? Try just this on a file named IPcheck.php
Code:
<?php echo $_SERVER['REMOTE_ADDR']; ?>
Navigate to it in a web browser. If it shows your IP address, then it's the forum script or the stop forum spam plugin. If it shows 198.91.81.5 then that's bad. I'm on xo2 and its working just fine. http://ttb.x10host.com/logfile.txt
at server date and time ==> Wed Nov 12,2014 09:40:22 EST America/New_York <==
x10hosting's free-hosting server [ xo4 ] is known - out here on the Internet - to have this issue
Just a note: if there's any chance that there's a proxy of some sort in front of your server (whether that's a local cache server, Cloudflare or what have you) you're almost always better off checking X_FORWARDED_FOR rather than REMOTE_ADDR.