PIC24FV16KM202, VREF+ Input Problem (robertvwhite)

I am trying to use the A/D converter in a PIC24FV16KM202 using an external reference of 2.55 V. When the device is in reset, the voltage on the VREF+ pin is 2.55 V. Once I start the chip running, the voltage on the VREF+ pin drops to about 0.35 V. I used ..