differentials fail... fulls and manuals successful... why?

[djmonolith]

After reading through the FAQ here, I have exhausted my resources. We are running Backup Exec Version 8.60 Rev. 3878 on Windows 2000 SP 2, IBM Small Business Server.

I have a new Backup Media Set running. The full backups are completing successfully, however the differentials are giving me an error on one remote backup. Here is the error:

------------------------------------------------------
Performing Remote Agent backup

Media Name: "Media created 6/24/2004 09:30:01 PM"
Backup of "\\MS\D$ "
Backup set #5 on storage media #1
Backup set description: "system backupiff"
Backup Type: DIFFERENTIAL - Changed Files
Backup started on 6/24/2004 at 9:32:26 PM.
The connection to the data to backup has been lost. Backup set canceled.
^ ^ ^ ^ ^

Backup completed on 6/24/2004 at 9:37:48 PM.
Backed up 804 files in 84 directories.
Processed 5,827,519 bytes in 5 minutes and 22 seconds.
Throughput rate: 1.0 MB/min
Software compression ratio: 1.5:1
-----------------------------------------------------



Here is same result for the successful full backup:

---------------------------------------------------------Performing Remote Agent backup

Media Name: "Media created 6/25/2004 09:30:05 PM"
Backup of "\\MS\D$ "
Backup set #5 on storage media #1
Backup set description: "system backup:Full"
Backup Type: FULL - Back Up Files - Reset Archive Bit
Backup started on 6/25/2004 at 10:10:51 PM.
The .DR file required for Intelligent Disaster Recovery is created/updated

Backup completed on 6/26/2004 at 1:31:21 AM.
Backed up 351858 files in 95 directories.
Processed 5,036,751,808 bytes in 3 hours, 20 minutes, and 30 seconds.
Throughput rate: 24.0 MB/min
Software compression ratio: 1.3:1
-------------------------------------------------------




Also, I have created a seperate manual backup of that same drive and it completes successfully every time. The problem is with the Differential. I have checked out NIC card based on a suggestion in this FAQ and everything seems OK:

"Realtek RTL8139/810X Family PCI fast ethernet NIC Properties

Link Speed/Duplex Mode = 100 Full Mode"

(Full Duplex isn't listed)


I am not sure how to check the Speed on the Switch...




Any idea why the differential keeps bombing out when the full and manual backups of the same drive are completing successfully?