/etc/zentyal/samba.conf is periodically overwritten by some obscure periodical zentyal process, taking /usr/share/zentyal/stubs/samba/smb.conf.mas as the template, so every modification should be made through this file or is going to be lost as soon as zentyal decides to do so.
I guess the -- antivirus settings -- is the part which concerns me, still can't figure out how to change the template to get the opportune modifications in smb.conf.
Btw couldn't understand what you meant in the last post, you mean there's no need to modify existent cron files?