I’m also having these problems. Localy (XAMP) it all works okay but uploaded to my webhost none of the pages (members, groups, profile, etc) works.
I’ve tried using the deafult theme and my own theme – no change.
I’ve tried without any plugins – no change.
It’s 1.1.1 and latest WPMU. I’ll see about trunk later on.
I’ve yet to put up another local installation or online. That will be the next step.
Like the first poster I’m using hostgator. How about you rfauster?