I am having the same problem with 10d. I was hoping that upgrading would solve the problem, but it sounds like 11d also is doing it. I too find that Network Backup-to-disk folders (NAS devices) are going offline during backup, I put them online and it only intermittently works. Although the share is available fine to windows.
Is there a way to make BACKUP Exec ignore or Retry putting the device online if it goes offline? It is only Backup Exec saying the device is offline anyway. This is a Backup Exec problem. Windows sees the Volume Mapped Drive with no problem. I don't understand the sensitivity issue and how can we control when the Mapped Network Backup-to-Disk Volume is marked offline? How can we automatically set the device to "ONLINE" without manually going in each time and marking it Online?
-Guy