[Koha] Cron job in KOHA 3.18 Configuring Error

Hi, I have installed the new version of KOHA 3.18 through apt-get on ubuntu 12.04 and i am facing a weird problem with cron settings i have configured it before for KOHA 3.16 it works just fine but the problem lies on the latest version, even with the default setting of koha cron also doesn't go well for fine calculation, process_message_queue, n others as well Is this problem related to zebra-daemon whichis newly introduced in 3.18 that needs to be activated for the cron's to run, or is the problem with the release itself. Any pointers would be helpful Regards Arunkumar