another thing I'd like to mention...if you could go into your inbox and outbox, and delete old messages you don't need, it would help keep the database smaller and easier to backup. There is a button to check the entire page of posts and you can delete them. I clean mine out every couple of weeks and its still a little time consuming. Don't forget the outbox ;)
if you go past the current page you cant view them so you might as well delete all of them. I cleared mine out
you actually can, but you have to switch to a non-modified PM theme (Ig Oh) then switch back. I'm going to update the forum software this weekend, and leave the PM mod out and see if we can live with it or not.