Windows 7 Task-Scheduler cannot reactivate my Dell Notebook

Hello,

I have a problem: My Dell Inspiron 9300 Notebook cannot be reactivated from Standby by the Windows 7 Task-Scheduler. Of course, I have activated the checkbox to reactivate the PC for running the schedule. But the PC doesn't wake up from Standby. It has to be a problem with the Dell Bios or something like this.

Does anybody have an idea?

Thank you!