Scripting Keychains

I am trying to script my keychains, and I’m getting an error even with a simple command like

tell application "Keychain Scripting" to lock keychain "art"

. The error message is “Application isn’t running”. I’m using 10.2 and Keychain is in /System/Library/ScriptingAdditions/. Anyone know why i’d be getting this error message

That should work. At least it does for me in 10.3.3. I’ve been using an idle script to lock my keychain when my screen saver starts at least since upgrading to Panther, can’t remember if I used it in Jaguar though. Have you tried

tell application "Keychain Scripting"
lock keychain "art"
end tell

I don’t know if you even can do that, but it’s worth a try.