I started having the same problem 3 days ago– just after my hosting service upgraded MySQL. I have upgraded to WordPress 2.3.2 to no avail.
I did have a little bit of success, by changing my reading options from the dashboard [dashboard-options-reading], to “show at most: x DAYS” vs. “x POSTS”. Doing this at least shows the most recent posts, but they are still ordered oldest to newest.
still shopping for an answer, but these occasional glitches are a nice way to make us dive into wordpress and understand it a little better, aren’t they? so easy to just take the software for granted