I get this error in the MAGT logs: IDispatch error #1277

I found this article relating to it:

BlackBerry Search Results

and this:

Error message in Exchange Serverxxx58; xxx34;The Delegate page is not available. Unable to access Outlook folder.xxx34;

Does that mean I need to recreate the BESadmin account and mailbox?

it happened after upgrading from 4.1.3 to 4.1.5.
I'm trying to apply SP 6 to see what happens, though i do have a feeling it's a mailbox issue.

Any ideas?

I would try to re-create the MAPI profiles before I would go about re-creating the service account.

This article helped resolve the issue:

BlackBerry Search Results

I've seen the 5302 many times before though I didn't see it in the logs for this one though I might not have looked closely enough.

Cheers.