Yes on the command line, -v -v -v gives the ps output.
But on the nagios web page (status information), I get only the 'ps' command line arguments.
Anyway, since my OP, I have encapsulated the ps command in order to mail the output to me. And since then, my problem disappeared ;-(
Since I have no more zombies, I can't no longer work on this problem.
If zombies reappear, I'll post a follow up.
Thanks for your input.