Upgrading mysql from 5.0 to 5.1

Ugh. So I saw there was a newer version of mysql out there (5.1) so I decided to upgrade the MacBook Pro to use it instead of 5.0. Before I did that, my Rails app was running fine. After doing the upgrade I started getting this error:

The bundled mysql.rb driver has been removed from Rails 2.2. Please install the mysql gem and try again: gem install mysql.

I've spent hours searching Google (and Bing, even!) for an answer, but haven't found anything that works. I've uninstalled and reinstalled the mysql gem many times, with different command line param combinations, no effect. I even totally cleaned mysql and the mysql gem off the computer (http://akrabat.com/2008/09/11/uninstalling-mysql-on-mac-os-x-leopard/), reinstalled mysql 5.0, and it's still fucked. I'm totally stumped. Put up a question on stackoverflow, but no luck yet.

I don't know how I'm going to fix this, and I'm dead in the water for development because of it. FUCK!!