I had loaded a new theme on my page. My best guess is that there was a script that was not compatible with my host (Yahoo! which is using an older version of mySQL) I ended up having to create an entire new one from my back up (I had to fully deactivate my blog and create a new one). Thank goodness for backups.
I had this happen to me today as well. Please post if you are able to find a solution. I am currently trying to load my backup via phpMyAdmin, and not having much success with that either.
