Can’t post with WP2.9.1

I upgraded to 2.9.1 and suddenly my posts aren’t saved. It just spins for a while and sends me back to the list of existing posts. I can’t even save a draft.

I am using php5, have already tried disabling all plugins and using the default template.

I’ve seen similar issues on the forum for 2.9 but not for 2.9.1

Thanks for any help.