I had some problems today but like I said before, all forums do that. I can almost guarantee that it is the host company either updating their DB's/backing shit up, or maybe the hardware node providing the shared hosting service is possibly unresponsive.
Of course there is a chance the problem is not the site itself, but rather a local problem with your computer, browser or possibly ISP. Since some people are accessing the forums only minutes after others received 404 errors I wouldn't dismiss this as a possibility. If you guys are having problems still (and you obviously can't fix the server side of things unless you are an admin) here are some fixes for all 4xx Errors, which are "Client Errors" (404 - page cannot be displayed, 408 - Timeout, etc.)
First off try switching browsers if that doesn't work then find the browser you are using in my list below and then follow the instructions given for that particular browser.
If you are using....
Safari If so then purging the Safari cache and rebooting should clear things up.
Firefox Than the following addon is a really handy tool created just for 404 errors and does so better than Google's "cached" choice -
https://addons.mozilla.org/en-us/firefox/addon/404-error/I.E. Stop using IE!
Opera Choose the option "Never accept cookies" and set it for the Chondritic address -
http://chondriticsound.com/forum/Google Chrome Clear your cache and cookies, then enable or disable the "suggestions on navigation errors". This is done by clicking the Wrench icon
at the top right, select Options, click "Under the Hood" tab and then, under the Privacy section deselect the "Use a web service to help resolve navigation errors" checkbox. Restart Chrome.
If this doesn't work than delete all cookies, caches and re-install
