Fast User Switching Doesn't Work Anymore


After Installing Tiger and updates up to 10.4.2, Fast User Switching doesn't work. It occasionally appears on the account of one of the users (my wife) but NEVER on mine as "System Administrator". It used to work before I upgraded to Tiger. Also, all of a sudden Entourage requires everyone to log in every time we want to retrieve eMaiI. It's as though the keychain has been damaged and doesn't remember anything.

I have done all the obvious things like making sure the Finder and system preferences are correct to no avail.

I have an "old" 500 MHz AGP G4 which I upgraded with a Sonnet 1.7 MHz CPU and 1G of RAM. Please HELP!!!!