Instead of wake-up, check to see if your bios has the option "reboot on power loss" or something like that. I had the option and always associated it with if I have a power failure, the sucker would restart when power comes back on. That's true, but it has nothing to do with a power failure. It simply means, when it gets AC, it turns on. So I've got my power bar wired so it turns on when the cab is flicked on, with the result, the power supply starts getting AC power, so it boots up the PC.
Hope I explained this ok, it works like a charm.