Mod_rewrite help

Hi. I’m developing a PHP message board/forum, and I’m making use of .htaccess and mod_rewrite to use “pretty URLs”. For example, the URL to my user profile would look something like this:

…instead of the usual query string mess like the following:

On my home testing server everything runs fine. But when I put it up on the DreamHost server, mod_rewrite seems to be acting weird. All of the “static” rules are working fine, but in any RewriteRule that contains “dynamic” things like ([\w-] ) or (\d ), the server redirects me to my 404 error page.

Any ideas on what could be the problem? I’m probably being pretty vague, so I can give out more information if needed.

Edit: Oops, this probably should have been on the troubleshooting forum.