When I put my Surface Pro into sleep mode (not hibernate, as I disabled that using powercfg -h off via command line), pressing the power button, Windows button, or pressing keys on the keyboard will NOT wake it up... the screen stays blank, although I can press the Windows key and feel it vibrate as to acknowledge that I've pressed it.
My only solution is to power off the device and then power on, which is not ideal for obvious reasons.
I have not made any changes to power profiles or the device, and I've spent quite a bit of time installing my software and copying files... I really don't want to reset it if I don't have to. I have already installed all available Windows updates.