Keychain problem

I am having a problem getting in to my usual Mac email system. This happened when I reinstalled Mac OS Panther. I can get into all websites etc. and Hotmail email, but not my Sympatico Mac system. I tried to get into Keychain to see if I had to get a new password as it didn't recognize my old one, however I only get an "error" and can't open Keychain. Thanks for any help.
George.