[Dave Flowerday]

Originally Posted by Biff

We are using 15K pots with 560 ohms feeding the ground side of two pots. Ie 7.5 k in series with the 560. Hope this helps.

You're only allowed to use 100K ohm pots on the OI inputs. Check the OI Reference Guide page 5. There's a good reason for this, and it's related to the the fact that there's a pulldown internally inside the OI (to force the 127 condition when the joystick is unplugged).

It sounds like your setup looks like this:

 
         15k                   15k
+5v ---/\/\/\/\------+-------/\/\/\/\----- +5v
                    |
                    \
                    /
                    \ 560 ohm
                    /
                    \
                    |
                  Gnd

If this is the case, check the wiring diagram again on Page 5. This isn't the right way to connect to the analog inputs.