MailItem Unload event fires non-deterministically with custom form-region

Hi all,

I've written an add-in that creates a custom form-region for reading/preview mailitems. In short, I've wired the Application.ItemLoad and MailItem.Unload events under the expectation those events will fire successively for aMailItem with my message class. That is,

* User selects mail-item A in inbox
* ItemLoad for A fires
* User selects a different mail-item B
* Unload for A fires
* ItemLoad for B fires
* User selects A again
* Unload for B fires
* ItemLoad for A fires

This is...

MailItem Unload event fires non-deterministically with custom form-region