Hi,
today I recieved my second NUC and I have same problem with two back USB port - they dont work. I had same problem problem with my first NUC (D43010WYK too), so returned it and they gave me new unit. I cant get anything to work - flash drive, printer, Bluetooth dongle. Front USBs forks fine (all on W8.1 x64 with correct drivers).
So I guess this unit goes back too.