As Josh Peek knows, if you're using SqlSessionStore (originally from Stefan Kaes of railsexpress.de) and upgrade to Rails 2.3, it will break.
I have a github version that I have updated for Rails 2.3, and also added a new "native columns" feature to. It is available here:
It is backwards-compatible with Rails 2.2 and earlier, so you should be able to update your application (probably worth backing up the old one just in case).
Thanks to Josh for all the help with this.
Nate Wiger PlayStation