Recently I had to troubleshoot a DPM installation that suddenly didn’t work anymore. After investigation (and having a lot of troubles finding something) I’ve noticed the following errors in the event viewer.
So I started to check everything on SQL level and discovered that the DPM jobs were running as a domain user (a so called service account with log on rights…)
So I looked at Services and discovered that the DPM instance and the SQL Agent for that instance were running under that service account.
After changing it back to the local user MICROSOFT$DPM$ACCT and restarting the server, everything worked back as a charm.
Hope it helps,
Read the complete post at http://scug.be/blogs/scdpm/archive/2009/10/17/system-center-data-protection-manager-2007-errors-by-example.aspx