Audio Systems: cd player not recognizing external hard drive, mass storage device, pioneer training

Question
my pioneer premier DEH-P6900UB deck will not recognize my western digital 120 GB passport 2.0 external hard drive. the deck should in theory support it, it can support a mass storage device up to 250 GB and has a powered usb, both use FAT32 file systems the led on the drive does light up...is this a driver problem or maybe a software issue?

Answer
i know the radio will recognize i seen that at the pioneer training
but they said that the external hard drive over 40 gb need more power the pioneer radio usb is not enough  you need to power the hard drive  from any other power source  and it  needs to be format  to a fat 32
it will work
good luck