I have a Dell XPS 15z. Under Windows 7, I was seeing the problem where Windows wouldn't resume from hibernation on every other reboot. In other words, I could cold boot, and it would hibernate and resume correctly multiple times. If I then did a Restart, when it tried to next resume from hibernate, it would fail, and do a cold restart, and then hibernate would work find again. There is nothing useful in the event log - all it says is that the last shutdown's success was set to false, and then it says "Windows failed to resume from hibernate with error status 0xc0000411".
I'm now getting the same problem on Windows 8.
Does anyone have any ideas? Is there any more logging or diagnostics I can turn on to find out more?