Published posts becoming unpublished.

I seem to be having a bit of an issue with posts getting set to unpublished about an hour or two after I hit “publish”. Worse than that, setting the post back to “published” uses an old revision of the post. It’s kind of annoying, but I’m doing what I can to narrow this down right now. Here’s what I’ve got so far:

I’ve been playing with a few plugins that might have caused this, so I’m going to shut them off for now and see if the problems clear up. *crosses fingers* This also started happening around the time the site was upgraded to WordPress 2.6.2, so I hope that has nothing to do with it. If anyone else is seeing this or has found a fix for this problem, I’d appreciate a heads up.