I have a MS-Exchange 2003 server I just recently setup. I installed Backup Exec 12 on the machine and it worked for a few days. Every since then, I've had this problem where if I tell it to inventory, erase, or eject a tape it will do nothing, and eventually the job status will be listed as "communication stalled." However, the machine does run its backups every night if I erase the tape in a different machine and stick it in there.
I have found mentions of this problem on the website but it always pertains to a situation where the client and server are different physical machines. In this case, this machine is not communicating with any other backup exec service or client. It is completely stand-alone. I've run all the updates from the live-update. Still no good.