SchedulerService not executed

Hello Experts,
Here is the issue,Iam trying to schedule a service say every Monday @ 9:00am in complex Tasks.Scheduler service is running on that particular time ,but not performing the Task(Service).after this we try to run the service manually it performs well and also if we setup the service for one-time Schedule service it performs good.But it is not performing well with Scheduler Service Setup.

Thanks in Advance .Please Mail me ASAP.

Naren

what are u seeing in the audit log for this service when executed through scheduler?