Wierd error as taking differential MS SQL backup

[Anton_Panyushki]

I 've got an MS SQL database that runs in simple recovery mode. In order to back it up I created a couple of backup jobs: weekly full backup job and a daily differential one. Full backups are taken good and well, but sometimes as differential buckups are taken the error message pops up:

The Backup Exec SQL Agent was not used to create the last full, differential, or log backup of this database. You must use the SQL Agent to run a full backup before you can run a differential backup or transaction log backup.
 

This error message is followed by the warning

The item SERVERNAMA\DBNAME is in use - skipped.

On the over hand other differential backups of the database in question complete successfully.

How do I get rid of this error?  

 

[newsolutionBE]

Hi

Please check this document to see if that relates in your case

http://www.symantec.com/docs/TECH58674

Thanks

[pkh]

Do you backup this database by using the built-in SQL backup?  If so, you should stop and only backup this database using BE.

[Colin_Weaver]

Also is this SQL database inside a Virtual Machine that is itself backed up as the Virtual Machine backup can affect the log sequence and cause this same condition.