I've gotten into the habit of locking my XP Pro workstation when I leave it at the school by pressing the Windows Key + L. I recently did some updates as per an admin's request (without SP2; we have SP1) and installed all the serious hotfixes. Now, I can't use this key combination (although I can use CTL+ALT+DEL). I don't want to log off but rather just lock the system.

Anyone seen this before? Any idears?

(Note: I've done a quick google and MS Knowledge Base search but not finding anything specific to this)