ColdFusion 8 Scheduler Stops Working

I have a ColdFusion server (Windows 2003 Server) dedicated to running scheduled tasks, and it has worked without incident for several years on CF 6 and 7. After upgrading to CF8, the scheduler stops working at random times (after a few hours or a few days), and the only way to start it up again is to restart the ColdFusion service. There appear to be no errors in any of the log files. I can log into the CF Administrator and successfully manually kick off the scheduled tasks, but they don't run automatically. Any assistance would be greatly appreciated.

Thanks, Corey