Exchange 2003 server, Outlook 2007 client.

Outlook works great except for one problem. When somone sends me a
calendar request where you accept, decline, or different time, my
responce goes to my outbox and hangs Outlook. After serveral Outlook
shutdowns, I can sometimes get to the outbox and see the message in
italics. After a few more shutdowns I can sometimes catch it as not
italics and delete it. Otherwise after a frusterating half hour I
have to reset my profile. Then after a few restarts will let me
delete the email.

I've repaired, and reloaded. Any ideas? No hints in the event logs.

Tango