I have a HTPC and it is set to sleep when switched off or when the system is on Idle for more than 15 minutes.
Up to an hour or so after I turn the PC off the remote IR reciever has no issues waking it up.
But by the next morning nothing other than a restart seems to wake the PC up. It then also places an error in the event log to say that it was unexpectidly shut down by me restarting the PC.
So it would appear that it wasn't truly off.
I have removed the Hybernate as an option so it should not be abe hibernate.

Is there a way to tell what's going on. I believe some mother boards or settings in bios put the PC into a deeper sleep , if so how can i check and fix this issue.