Hmmmm.. seems to me that forum.php would be inside the "board" folder.
Are you using VBSEO or some other re-right plugin? It could be an htaccess issue. Do you have an htaccess file. I see your landing page at
www.mjworldcry.com.
How do you get the non-dynamic URL
www.mjworldcry.com/board instead of the standard url
www.mjworldcry.com/board/index.php ?
Be sure to go to your config.php file and disable hooks there as well using the code I posted before.
You will probably need to create a new, unaltered style with the plugins disabled to see if you can get your forum to work if it is not a htaccess or some other re-right issue.