Noticing a couple things. I closed my type cover and peeked to see if the screen turns off. It does after a couple seconds so I assumed it went to sleep. I put the SP3 in my bag for a couple hours. When I took it out, the device was warm and I lost a lot of battery which led me to believe the device may have not been sleeping. Since then, I now press the power button to sleep it before closing the type cover and have not experienced it again. When I open the type cover, the device does not wake up. I always have to press the power button. It does not matter if the device is asleep for 5 minutes or 5 hours, the screen does not turn on when I open the type cover. I mention the duration of sleep since I read that the device goes through different stages of sleep/hibernation. Has anyone experienced this with opening/closing the type cover? I'm still within my 15 day return if I have to exchange anything. Its not a huge deal that I have to press the power button. I had the original surface RT and had no problems with opening/closing the type cover. My device is updated with latest firmware and other updates from microsoft.