I've noticed several variations of this problem in this group, here's
mine...

When performimg a scheduled backup of my Exchange 5.5 Directory Store and
Information Store, if fails with the error...

"Unable to attach to \\SERVERNAME\Microsoft Exchange Directory. The device
cannot be found."

The IS backs up fine. Also, if I run the job manually, it completes
successfully.

Here's my config..

Backup Server:
-Windows 2000 Server SP2
-Backup Exec 8.0.3316
-Exhcange Administrator Installed

Exchange Server:
-Windows NT4 SP5
-Exchange 5.5 SP3

Any ideas?

Thanks,
-Jason