From: Tom P. on
I don't know where I found it but I saw somebody suggest a
GC.Collect() to clean up the RPC handles (or something).

Believe it or not - It Worked!

I think it had to do with filling the ComboBox without releasing the
resources, but one little GC.Collect() and it's casting it MailItem
just like it's supposed to.

Thanks for the help guys.

Tom P.