Norton Save and Restore is really Ghost 10 and the "agent" is the service.
Click start and in the run box type: services.msc
press enter to open up the list of services.
I can't remember what the service is called, it may be called
save and restore
Norton Save and restore
or maybe even Norton Ghost
If you find it, it should be started, if it is not try starting it and verify it is set as "automatic".
With the service running try doing another backup.
Dave