Something really buggy is going on.
I have a lot of writers set to the "contributor" level. This is so they can write posts, save them as pending, then let me approve, edit and post them.
Suddenly, no one at the contributor level has the ability to post anything.. it's just plain gone. I was using a plugin for a while that gave more complicated roles, but that never caused a problem. I've now disabled almost all plugins and the ability to compose a post is just plain gone!
Is this a common problem? Could this be some much deeper problem with the data base?