Thanks for both of your suggestions. I did run some diagnostics on my server, and backup last night.

My backup is always in nonpeak hours at night, so user load shouldnt be an issue.

The next thing is I did a backup job without the Symantec Open File Option, and It came out allright. SQL server didnt generate any errors.

This is quite strange, because Its been working fine the last couple of months, when it suddenly started with these errors.

Bottom line is I now localized the error, the Symantec Backup Exec 11d Open File Option. An I will therefore continue troubleshooting my problem with symantec.

Thanks for your responses 🙂