Access to most admin functions lost for user 1

I have this site that's been having some problems with Content Access lately. Over the last couple of week, trying to do anything complicated, like creating a view or CCK fields, often results in hitting my memory limit (a separate issue I'm dealing with my host about). Sometimes when this happens, content access gets all screwed up - I can't access anything, sometimes even for anonymous users they can't access the homepage - or any pages, etc. Usually, after fooling around enough I can make my way to Rebuild Content Permissions, and all is restored.

But this time when it happened, things are really bad, and I can't fix it. As user 1, I can only access a very limited set of admin items, and rebuild content permissions is one of those that I can't get to (see screenshot for list of things I can do). I can't get to modules to disable content access, I can't get to settings/performance to try to flush cache.. I tried rebooting my server, but no change.

Can anyone suggest how I can fix this?

The only access control modules I'm using are content access and workflow access, but I'm pretty sure it's content access that has been giving me grief. I only use this to control access to a few pages.

Please help!