@pperreira Whenever i hit that problem i would navigate to the call requests to see if the call had been queued,
http://localhost:8008/admin/dialer_cdr/callrequest/, all the time I would find that there is no entry of the request and I would have to restart celery according to the troubleshooting guide. My experience was that I would have to restart celery several times or even reboot before things started working. Since the upgrade to 1.2.12 i have not hit that problem you may want to upgrade to the latest version if you are not already on it.