My engine goes to quiescent mode

A few weeks ago and until now my instance always go to quiescent mode.. I had check the online.log file and found that my instance did not going on the right directions...before this problem happen i had make scheduled that everyday at 1.00 am it will reboot using crontab...For your information the informix version is IDS 7.3 running on solaris 7. any response from my question i like to say thank you very much