Happens to me so I tried different settings, turned off all background runners that I was able to, that fixed the battery problems, I bought a cheap charging plate off ebay, laid the phone on the plate it started charging but in the morning it was off (missed the alarm), the following night I turned off the wifi & bluetooth ( don't need them when your asleep), it has been 2 months since doing this & the phone has not shut off at all, when the alarm goes off in the morning I just turn on the wifi & bluetooth, it seems to be a problem with either wifi or bluetooth for some reason, I wiil try shutting down 1 at a time to prove which one and will post the results, now if only nokia/windows will allow me to change sms tones to what I want I will be extremly happy
Cheers
Crackers