I have been unable to get posts to save when I include the Post Title field. I have been able to include all (at least I think I've tried them all) the other fields and have the form save. Even if the only field I have in the form is the post title field it won't save and gives a warning to contact support.
I'm on 1.6 beta 1 WordPress 3.2.1 with no plugins running (at least while testing). Even with debug set to true I don't see output outside of the message to contact support