That I can answer - Windows Update.
Lol. I hate windows updates... possibly can be because of it.
@OP
If you open up the case of your keyboard and feel the microcontroller, is it physically hot? Maybe a short somewhere, pulling a lot of current (hence overheating). I totally want to fix it...@_@
I'd try and get warranty if that's still valid for you. Reselling it may get you a bit back. I'm kind of interested actually. Only if you are UK and offering for cheap (and I mean real cheap...). ><. Otherwise someone will want to pick it up; For the case/switches/keycaps.