sleep - Task scheduled to wake laptop - only works when lid is open

I am running Windows 7 Starter on an Acer Aspire One laptop.

I want my laptop to automatically run a task (backup the HDD to a network drive) once a week in the middle of the night. I scheduled the task in "Task Scheduler" and checked the box to wake the computer to run the task. I also changed the advanced power settings to allow wake timers. This was half of the solution. It now works flawlessly when the lid is open... the computer can wake itself up from either sleep or hibernate mode to perform the backup. When the lid is closed however, its sleeping beauty.

Any ideas? I don't want to have to remember to open the lid once a week. It sort of defeats the purpose of an "automatic" backup.

Update: I discovered that it can wake from sleep (or hybrid sleep), but not from hibernate when the lid is closed. This is good news. I'd still be curious about how to get it to work from hibernate, but I'm pretty happy about waking from sleep at least.