Here's what I did to get the profiles to show up without the modules using J1.5.8/CB1.2RC4/Sef OFF
RewriteRule ^([^/]+)/?$ index.php?option=com_comprofiler&task=userProfile&Itemid=28&user='$1' [L]
The trick is to put in the "&itemid=" in the rewrite statement. I don't know if "28" is standard for all installations but it should be. Now, when you type in the short url, you get the profile to display without the front page modules.