Exchange 2010 - Resource Calendar Issues w/ Outlook 2003

This morning I came in to an e-mail from a user having trouble connecting to the calendar of some resource mailboxes I recently migrated over to Exchange 2010. He could open one of the three just fine, but the other two gave him the following error:



I checked to make sure he had Encrypted communication to the Exchange Server enabled and he did, and I also verified he was running SP3 on Outlook 2003 which he was. I did some searching and came upon this post on the Microsoft Technet Forums: Linkage.

From that thread it seems like there is an issue with Outlook 2003 connecting up to shared calendars on Exchange 2010 that at least according to that thread will be fixed in Exchange 2010 Rollup 5. I couldn't really wait that long, so I went ahead and migrated the user's mailbox over to Exchange 2010 ahead of schedule to see if that would fix the problem. Sure enough, once his mailbox migrated and I got his Outlook pointed at the new server he could connect up to all 3 calendars just fine.

Not exactly the solution I wanted at this point but it's better than nothing.