Vista sleep doesn't work, only hybrid sleep does

I seem to have a problem with my new Asus G1S and the sleep function in Vista Ultimate (plugged in, I haven't actually gotten around to try it on battery yet).
When I've got "allow hybrid sleep" turned on in the power profile it correctly "quiets down" after saving the session to disk when I hit the power button, leaving only a green light turned on at the front of the laptop.

Regular sleep mode seems to cause problems though, as does any automatic "put the computer to sleep after" settings, even if I've got hybrid sleep set to allowed.
When I hit the power button the screen goes black and it starts accessing the harddrive and pretty much behaves like it does when it (correctly) enters hybrid sleep - only it never stops, it just keeps trashing around on the harddrive, and the only thing to do is to hold down the power button for a few seconds for a forced shut down (and when I boot up again I'm then presented with the "Windows wasn't shut down correctly - safe mode/load normally" screen).

Anyone who have experienced similar problems, and is there a way to resolve it? I'm about to finally try plugging in the battery now, but if it shows the same problem I imagine I'll have ended up with a laptop that's less efficient on the road than it ought to be, when saving battery is an issue and (automatic) sleep would be great help.

 

Well, regular sleep appears to be working as intended when it's running on battery.
I guess it doesn't really matter if it's causing trouble when the laptop is plugged in then - I'll be using hybrid sleep anyway when I "shut it down" for the night.