SBS 2003 on server, Office 2007 on clients boxes. All Updates. User A has user B as a delegate and shares his cleandar with B also. The delegate permissions are only for contacts so she can view and add contacts to his. She does not have any delete permissions at all. She will make a request for a meeting. Send it to him. He will accept. It will go into his calendar, then it will disappear. Happens sporadically. Sometimes immediately, sometimes it takes awhile. There are about 15 users at this site. We only have issues with this and another user whose sent items disappear randomly but I have that in another thread. I don't think there is a connection between these two but who knows. I have searched the web but have not found a solution that works so I am throwing it to you guys.