Does Backup Exec 11d 'Throttle' data as it backs it up?

We have recently deployed a new CAS and mysteriously, the jobs now take twice as long.  The old server sits literally inches from the new one.  The data in question backs up from a data center approximately 200 miles away.  We have a 9mb pipe between here and the data center.  This all worked fine until we installed BUE 11d onto this new box.  If we copy a large file just using Windows Explorer drag and drop to both servers, the time measured is the same, but when backing up the same file, it takes twice as long on the new CAS as it did the old one.

Has anyone else experienced anything similar to this?