Well, after a number of updates the surface pro 3 going into a permanent sleep mode seemed to be happening less often. Appearances are so deceptive. Now leaving it on battery and with the keyboard attached, it goes to sleep after 4 minutes as it should, and after a couple of minutes that is that. Comatose. Keyboard remains illuminated but no way to awaken it. Has to be rebooted. I have to say I have never had any equipment that has more bugs than the surface pro 3. Downloaded the latest updates today. No change. No way my staff will be getting these- not fit for purpose unfortunately.