So far I haven't noticed the black screen issue after playing with a fresh Windows 8 install on my tablet. There was one time it did occur, but it went away relatively quickly. Surprisingly, as soon as I took the tablet out of the case it started working again. I looked further into this, and there are certain 'pressure points' near the bottom of the tablet's front (left and right of the Windows key), that if you push on it a certain way, the screen glitches out briefly. I'm thinking there might be a loose connector or cable under it, which maybe the case I had on was agitating. So it very well could be a hardware problem. Since removing it from the case, everything on it has been perfect. If you have a case and the same problem, try removing the case. As for Windows 8.1 Preview and battery issues, maybe it's just because it's the preview edition? It's a pre-release OS, so there's probably still bugs in it. Try Windows Update, or messing with your power options a bit.