You know what, I found my problem. It's not yours. (Sorry!)
My problem is that my spyware blocker/hardware cleaner gets rid of the DirectX stuff that's needed for SE to work. Once I ran the installer again, I was back on!
Sooooo, I just have to re-run the installer the next time I can't get on, and I should be fine.
Edit: And, by the way, Woohooooo! I got level 4 too! /Edit
***Hey, does anyone know where I can go to refill my magic? The inn doesn't heal it. Do I have to use items? (Or do I have to die? I know that refilled it...)