Just to close this up. The mysql database was corrupt. I had a friend of a friend who knows how to do this stuff do a clean install of mysql (I think that when I installed it over the previous one, it didn't create a new mysql database or something). He was then able to import the mysql database for ubb.threads back in and got everything working again. I'm not sure about the details of what he did, but it worked.
Yeah! And I was just about to order eve...
