Slow tape backup of DFS replicated Folders

I have Win 2003 R2 network and use DFS to bring data up to a central
server. I have approximately 100 name spaces so that each remote
location can map to its own name space. The data replication is fine.
Backing up the central server to tape each night is just rediculous. I
use CommVault to backup the files to tape. Right now it takes about 24
hours to put 700GB onto tape. Hardware seems to be ok. No failures on
diags. I have tested the latest Backup Exec solution from Symantec as
well.

We have found that you can select the files in a different manner in
Backup Exec and it seems to be speedy until you add more file
selections. The CommVault software seems to run at the slow throughput
no matter what. I have stopped the DFS service and this seems to help
Backup Exec some but has no effect on CommVault.

Is anyone else out there using DFS and experiencing slow tape backups
with DFS. I think this has something to do with the DFS and not the
backup software. If anyone else has had this problem and moved to a
superior solution please let me know what you implemented.

Thanks so much