JJSosa - thanks for the link, I'll check it out.
Darcos - cool, good to know. I'm not using linked-mode currently, and won't after upgrade, most likely.
smitchuson - your environment is very similar to mine then. So to clarify, in your situation, you have two instances of SSO? One for each server? I thought I looked at that when 5.1 came out and it was not possible due to the tables that were created for sso. Maybe I was wrong, or maybe it was fixed in 5.5? Sounds like the way I want to go though.