Restoring Exchange mailbox folder

I'm trying to restore a folder from a mailbox, which is on a duplicate backup tape.  I have catalogued the tape.  The folder is approximately 60MB.  The restore job is in the state of "Staging" and the byte count is at 40GB.  I feel like it's staging the entire mail store before it will restore this folder.  In the past I've been able to quickly restore single emails or mailbox items quickly as if doing a file restore, although it has been from the disk backup.  Is this the way it works when restoring from a duplicated backup tape?  Any help with understanding this process would be appreciated.  Thanks...