Windows Task Scheduler, Wakes up then sleeps

Hi, I use EPG grabber to update my TV Guide every night. I have set up a Windows task Schedule to do this. It works by waking up the computer at 4am then runs and the computer is put to sleep at 4:40am.

When I go in the morning to turn the computer on the computer wakes up, I see the media portal screen, then 1 second after it goes back to sleep again.

The only way ive found of fixing this issue is to create a seperate wake up trigger which brings up a message box. This fixes the wake up issue, however there is now a message box in the way and I must click ok to get rid of it each morning, annoying.

I am running windows 7.

Many thanks.