V-79-57344-766 - Cannot log on to MAPI

[SummitMIS]

We are recieving the error "V-79-57344-766 - Cannot log on to MAPI with the specified credentials." when backing Exchange 2003 to disk.
The same backup works fine to tape, and it has worked fine to disk in the past. It will work for a week or so, then stop working again. We have made sure our backup exec install is patched to the newest version. We have deleted the entire job and started over, which makes it work for a few days then it fails again with the same error. We have tried every solution listed in the KB with no success.
We are running Exchange 2003 SP2 on Windows 2003 Enterpeise Server SP2 BackupExec 12.3.
Unfortunetly most of the suggestions we have seen apply to Exchange 2007 on Server 2008, but that is not what we are using.

[SummitMIS]

bump

[HAMZAOUI_Omar]

Hi,

Be sure that MAPI CDO are installed on Exchange Server.
When you create the selection list, can you see Information Store?


Regards

[SummitMIS]

Hi,

Be sure that MAPI CDO are installed on Exchange Server.
When you create the selection list, can you see Information Store?

Regards

MAPI is installed.
The information store can be seen. As I said in my original post, the backup was working fine, and works fine to tape, but not periodiclly fails to disk. Sometimes it works, some times it does not with no pattern.