K, I had the same problem and figured out how to fix it.
I think it had to do with the fact that I renamed and totally re-wired the theme info at the top of my style.css AFTER I had already switched to it. What this did is somehow make the WP theme system think I was assigned to an invalid theme.
To tell, go to Appearance > Editor. I got a short message that “Your theme is not valid” or something…
All I did to fix was go to the theme chooser, re-choose my theme and it was all fine..
good luck!
