I have a six month old Dell XPS with Vista Home Premium that has begun, as of yesterday, to not want to stay in sleep mode. It will initially but it seems like something "wakes it up". I have not messed with anything other than I did a manual virius scan yesterday for the first time with Norton. It does it automatically every night but I did a manual scan, come to think about it, I did the scan because I noticed this problem and thought I might have a virius running in the background but everything checked out. I usually just leave the computer running and it puts itself to sleep, now I feel like I have to turn it off for the night, anybody have a clue?