That I recall a similar issue I had many years ago when these parts were first released - may I say I was appalled at the scant documentation this line of product had, hopefully it has improved over the years. My hazy memory recalls something like some pins need to be held in certain states when the device is reset so that certain ports are configured properly. But then again, I could be wrong! Have a really good read of the datasheet to confirm/deny my prognosis. The fact that it works on the EV board and not on your board would tend to support this. Failing that, check your code and check the power pin wiring to the chip.