Mike,
While this probably isn't the problem, if you haven't tried it it couldn't hurt. Can you access the forum from your browser by typing in the IP,
http://65.127.237.190? If that doesn't work, and you are using Windows, try typing in the following from a DOS prompt; PING forum.portraitartist.com, or PING 65.127.237.190. If pinging doesn't come back with a several replies in milliseconds for the forum command, but does for the IP number command, then that most likely means your internet provider lost the domain name from their list, and needs to add it again.
Holly