Here's a copy/paste from an e-male:
First allow me to apologize for this unexpected and much too long down time. I don't have 100% of the facts yet but the problem was within the DNS server change over, if you want to know - email me back and I will reply as soon as I get all the details of the event.
for now you can access the site using this ip address:
http://207.44.142.144//forums/index.php?s=
that is the new ip that the DNS servers are STILL not seeing. But this is changeable from within your own windows directory. To make the change to the xtremesystems.org link follow this step:
You need to copy and paste the following into your HOSTS file (C:\WINDOWS\system32\drivers\etc - use Notepad to edit it)
207.44.142.144
www.xtremesystems.org