I can report that this issue started occurring with my Surface, too. I never experienced it for several months, where I didn't have the type cover, but now it is getting more annoying every day.
I unplug the Surface in the morning and plug it back in when I set it up at the office. I never disconnect the keyboard, really. Usually, it succeeds in waking up. However, after coming home the last two days I had to use the two button restart methods explained
above in order to see anything.
Frankly, this is annoying. I noticed before that Surface tends to be a little on the slow side when it comes to responsiveness after waking up. But with the keyboard attached, sometimes I need to wait 5 seconds until it shows any sign of life, other times
it doesn't wake up at all or the screen backlight turns on, but all I see is black.
Seriously, this needs to get fixed. I don't think I am doing anything weird with the device. My usage pattern is probably pretty much what the Surface was made for.
I have checked the maintenance reports and I am getting the same picture as some of you guys have posted here. Basically, there has rarely a day gone by without a critical hardware error. Most of the time I don't really notice those errors, but today, it
seems that the times the two errors occurred are pretty much consistent with when I closed the lid for a lunch break and leaving. However, only the second one left my Surface unresponsive and sometimes there is no hardware error at all just before I have to
restart.