wp3.1 upgrade left site malfunctioning

I updated to 3.1 just yesterday, and for a long time I was getting a 500 error. Now I replaced my config file with a blank one and filled it all out and still got the same thing until I created a new SQL user and pointed the config at that, and now everything is just a blank page.

I suppose it could be a theme or plugin issue, but I would think there would be an error message and either way I don’t know what to do next.