[daltore]

A little background on the 10k potentiometer value in the manual:

The Luminary Micro ARM processor that's in the Jaguar operates off of 3.3v, but the ADC is only 3v tolerant. They have a 1k resistor connected in series to the power pin on the pot input on the Jaguar, so you have to use a 10k pot to cause a voltage drop across the 1k resistor of .3v and the voltage drop across the entire potentiometer of 3v.

By using a 100k pot instead of a 10k, you're causing a voltage drop of 3.27v across the potentiometer. This means that if you pull the pot all the way down to its minimum resistance, the ADC is experiencing 3.27v, which is .27v greater than it was rated for. This might be why you had sporadic results.

If you don't have a 10k pot on hand, don't use a lower value, as that will cause more current to flow, which is also not necessarily good. If you have some spare resistors lying around, try putting them in series or parallel with the two extremes of the potentiometer to achieve 10k. This may reduce your resolution, but it won't break the Jaguar. If you don't have any resistors, wait until the next day.

This is just my take on it, if it works fine for you, go for it, but it may or may not be risky.