Power Management Problem?

I’m not too sure what’s going on here, but my laptop is all of a sudden having an issue coming back up after I close the cover for awhile. Everything will be fine, then I will close the cover and come back a few hours later and all I will get is a black screen or my background with no icons. I’ve tried ctrl-alt-delete and even the power button, but nothing works. I literally had to disengage all power to get it to shut off. It boots back up fine, as if nothing happened. I know that there have been similar issues with standby and hibernate, but I have both of those settings set to never. I’m thinking it may be a power management issue, but I’m not sure where to start. I’ve had my computer for almost a year, but have never seen this before. Any ideas?

BTW, I have Windows XP, SP2.

 

Are you using hibernation or standby?

 

I have both of these set to never. That's what's so strange about it.