I've been getting this message about "Keychain Not Found" in many applications such as: Safari, Camino, CyberDuck, and Adium. It's really annoying and appears pretty often. It just started doing this a few days ago. Not sure why. Here's what the window looks like:
http://salsunproductions.com/misc/keychain_not_found.jpg
http://salsunproductions.com/misc/keychain_not_found.jpg