My Dell XT, after upgrade to windows 7 ultimate seems to never recover from a sleep i.e. opening the lid shows a flicker, and then all lights go off. When I press the power button long enough it reboots and says that Windows had a serious error, blah blah (but no BSOD). Hibernate doesnt cause any problem, and that is what I am doing as default. Any idea how to debug more and fix it. Looked around (on web) for answer, tried related solutions (hotfixes for similar but not same problems) etc, but noting fixes this.