I notice that sometimes when I unplug my n4 it won't wake up or turn on. 9out of 10 times my n4 will turn on and I can look to see how many missed calls or text messages I have, but sometimes the screen stays blank. I'll hit the power button to wake it up and nothing. But after a few minutes it will finally wake up. Very weird and I hope it doesn't start to become an issue later on.