Cannot backup System State on 2003 SP2 Domain Controller

[RStovall]

I have just installed BE12.5 and am unable to backup the System State of one of my DCs.  The DC used to have the 9.1 agent installed, but it has been removed and the 12.5 agent installed.  The ADRA option is licensed and installed on the media server.

I have tried to run a couple of System State backups and each has failed with the following errror:

Backup- \\servername.domain.com\System?State Unable to attach to .
V-79-57344-33899 - The resource could not be backed up because an error occurred while connecting to the Backup Exec for Windows Servers Remote Agent.

Note: Click 'Edit Selection List...' to display the View Selection Details tab of the job's selection list. Select the entry with the server that no longer exists and click Delete to remove it.Edit Selection List...
Make sure that the correct version of the Remote Agent is installed and running on the target computer.  If the server or resource no longer exists, remove it from the selection list. Edit the selection list properties, click the View Selection Details tab, and then remove the resource.

Additionally, there is mention of "Final error: 0xe000846b" in the job status and a link to article V-79-57344-33899.

The BEremote service never crashes on the DC and no unusual events are in the system and app logs of the DC.  Event 34113 is logged in the application log of the media server.  The DC backup fails after a fresh reboot.  The target for the backup is a B2D folder located on a CIFS share on a Data Domain DD530.

Any hints or thoughts?  I've gone through the KB article for V-79-57344-33899 and none of the links seem relevant to this issue.  The account the media server uses for access is a domain admin account.  The account for BEremote on the DC is local system.

The last bit of information is that the System State backup job copies ~1.2GB of data across the wire and seems to do fine.  At the end the job status goes to "Updating catalogs" where it appears to hang before eventually failing with the error above.

Thanks for any help,
RS

[RStovall]

Forgot to mention that the GRT option is enabled on the backup job and the IMGXXXXXX folders are created on the B2D folder and populated with data.  I just ran a System State backup of this DC without the GRT option and it completed successfully.

The issue also gets more frustrating in that my first Exchange GRT Information Store backup (on a different server which is not a DC) just failed with the same e000846b error.  If it matters, the AOFO option on both servers is set to automatic and VSS was used according to the log.  Both servers have recently been updated to Server 2003 SP2.

Thanks,
RS

PS  What, if anything, should I do with the IMGXXXXXX folders on the B2D folder?  The components don't show up as being 'restorable' In BE, yet the information is sitting on disk taking up a significant amount of space.

PPS  Here are the settings of the Exchange job that failed:

General

Job name:  Exchange Full Server Backup
Backup set description: Exchange Full Server Backup
Backup method for files: Full - Back up files - Using archive bit (reset archive bit)
Compression type: None


Verify after backup completes: Yes

Advanced

Set Remote Agent priority: Normal Priority
Open file backup when Advanced Open File Option is not used:  With a lock


Enable single instance backup for NTFS volumes: No
Back up files and directories by following junction points: Yes
Back up data in Remote Storage: No

Advanced Open File

Use Advanced Open File Option: Yes

Open file configuration: Automatically select open file technology

Process logical volumes for backup one at a time: Yes


Advanced Disk-based Backup

Use offhost backup to move backup processing from remote computer to media server: No


Microsoft Exchange

Exchange Server backup method:  Full - Database & Logs (flush committed logs)
Mailbox backup method:  Full - Back up messages - Reset archive bit


Continuously back up transaction logs with Backup Exec Continuous Protection Server: No
Enable the restore of individual mail messages and folders from Information Store backups: Yes
Enable single instance backup for message attachments: No
Perform consistency check before backup when using Microsoft Volume Shadow Copy Service (VSS) snapshot provider: Yes

Continue with backup if consistency check fails: Yes

[RStovall]

The problem turned out to be the DD530 appliance hosting the B2D folder.  I found another series of posts which described similar problems and the answer there was to update the OS of the DD530.  I updated to the current DD OS version 4.6.3.7-123873 from 4.6.1.0-88314 and all is well with the System State backup of the DC.  I imagine that the Exchange backup will be OK as well.