I never solved this... I think it's not possible to do... ;-(
This is what I did:
Create an error file, when everything went OK, delete the file afterwards.
When something went wrong, make a new script that copies the error file to a specific WS.(witch is started after the backup is finished!)
Startup the services a few hours later when the backup is finished. So that all the services are started, even when the tape has crashed!

I could post you the whole script if you want to, but I'm not working for that company anymore... a friend of mine still does! ;-))
The script that I've put together worked for me and never disappointed me...

I'm not at this board quite often, but you can mail me at slminc90@yahoo.com if you want a quick response...

Grtx, Kir@