Thanks Bingo, it's not what I wanted to hear, but it's an answer.
So, for now, the only solution is stop/start NW.

John
________________________________________
Van: EMC NetWorker discussion [NETWORKER AT LISTSERV.TEMPLE DOT EDU] namens 
bingo [networker-forum AT BACKUPCENTRAL DOT COM]
Verzonden: maandag 13 mei 2013 20:06
Aan: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Onderwerp: [Networker] Removing stopped sessions

The problem is that these jobs are not listed by jobquery/jobkill any longer. 
It is obvious that kill is not an option.

So far, not even EMC has a solution for these issue which is extremely 
confusing for finished browse/recover processes.

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