Going back to your original post:
>> On my fighterstick on the X axis with the stick held left it would read something different each time...
Such as: 6, 21, 3, 25, 35, 15, 7, etc etc... never the same reading. <<
Is this still happening? If it is, I'd still bet on bad connections at the pushon connectors that they use to connect things to the pots. It shouldn't be that bad. Noisy power maybe, try a motherboard port, you might check that the trim wheels are centered, but until you can get that to stabilize it's line up.
To answer your question, all pots are off-center at least a little. If you're watching in the Control Manager Raw Data display, center should be ideally 128 but it's hard to hit it exactly. Off-center won't cause the kind of jitter, though, it's just off-center, and the calibration routines do the arithmetic on the values at left, right, and center, to get the stick to line up, it will take permanent offset out. As long as it's jittering that much though, it's going to pull to the right. High values are right and back. The left end keeps bouncing around, that makes the average value higher and pushes you off to the right. The calibration will fix "off-center", but it can't contend with that jitter.