Strange OI potentiometer problem

[ubermeister]

I'm trying to put a POT into our teams custom OI box, but I can't seem to get it to work properly. Here's the setup:

A 100k linear-taper Radio Shack POT is connected between pin 1 (+5) and pin 6 (Y-axis) of port 3. The wiper (center tab of POT) goes to pin 6, and the left tab goes to pin 1.

When hooked up to a program to repeatedly print out the value, it only prints 254.

Now heres the strange part-
I took a multimeter to the pins of the 15-pin connector. The custom POT sweeps between 0 and ~97k ohms between pins 1-6, and a commercial joystick does the same thing. The catch is that the commercial joystick works (value varies between 0 and 254) while the custom POT doesn't (stays at 254).

I have read the OI reference manual, and as far as I can tell have wired it exactly how it specifies.

Am I missing a pin somewhere? Is there something stupid I'm missing or is everybody else as confused as I am?