Recently migrated a client to Exchange 2013 from 2007. 2013 is running on SP1 (CU4).
The 10 resource mailboxes (all rooms) after the migration are not behaving properly. All of the resources had Booking Delegates on them. Per request, I removed the Booking Delegates and set it to auto accept/deny and not allow conflicts.
1st. If a user sends a calendar request to the room, they receive a confirmation email back but it still says it was on behalf of the booking delegate (despite them being removed as a delegate).
2nd. Free/busy doesn't seem to be working for the migrated ones as they always show as Free. In addition, it auto-accepts all requests even if there is a conflict.
I created a new room mailbox with default settings without a booking delegate, it behaved as expected and desired. Free/busy works for it too.