I followed this forum and tried everything mentioned, even started deleting all my apps one by one, but still running at 100%. I decided to go ahead and do a fresh factory reset and wallah it works! My phone now sleeps as it should. I installed handcent and have been using it to avoid the issue coming back. I think those of you that are still having the 100% issue even after the SMS fix may want to bite the bullet and do a reset. It wasn't too bad since I have all my contacts setup on google and not on the phone so it automatically sync's them, even kept all my custom pic's!
Only had to re-link my ringtones.