Many users logon/logoff in event viewer: ID 538/540

From: Alvin (Alvin_at_discussions.microsoft.com)
Date: 01/31/05 

Date: Mon, 31 Jan 2005 06:51:03 -0800

In my event log (security audit) I've noticed several users on the domain
appear to logon/logoff on my computer. I don't have any open shares. What is
this?

Thanks