hi marcello, 

jettagmontool issues ~2000-line messages. 
+verbatim+
toolsvc.jettagmontool                                info bin: 300 rate: 0 error: 0
toolsvc.jettagmontool                                info bin: 0 hrate: 0 herror: 0
toolsvc.jettagmontool                                info bin: 1 hrate: 0 herror: 0
toolsvc.jettagmontool                                info bin: 2 hrate: 0 herror: 0
toolsvc.jettagmontool                                info bin: 3 hrate: 0 herror: 0
... ...
toolsvc.jettagmontool                                info bin: 1999 hrate: 0 herror: 0
toolsvc.jettagmontool                                info bin: 2000 hrate: 0 herror: 0
toolsvc.jettagmontool                                info bin: 2001 hrate: 0 herror: 0
-verbatim-
https://atlasrtt.cern.ch/rtt/rel_1/17.0.x.y-val/build/i686-slc5-gcc43-opt/offline/recjobtransformtests/amitag_q122/esdtoaod.log
you should be able to suppress bins with zero-rate and zero-error. 

cheers, 
susumu 