Fud,
the cord that connects the throttle to joystick is often the reason for loss of calibration.
What I did was use a set of splitring plyers and spread the sheild that surrounds the pins to make it hold in postion better.This basically tightens the conection,you dont need "splitring" plyers to do this the just work well and I own a pair.
There a split in the sheild and you could insert any small screwdriver,nail etc. into it to spread the sheild slightly.Once you've done that you could use some tape or stickyputty or the like to help hold it in place but if done correctly you really shouldnt have anymore problems as long as you "powered" hub is good.
CAUTION: please be careful to not break or bend the end conector,however they can be readily bought at any electronics store.
I dont recall the type on conector,PS2 maybe.....
Give this a try and report back if the issue persists or not.
Hope that helps!