Note Variation Slider Problem

Hi there,

I just got an MPC2000xl and I think the slider does not work!
Example:
If I assign the tuning of a Sound to the slider, the sound is played as if the slider is all the way down. Moving the slider has no effect.

I have read that I can use the slider (plus shift-key) to select something. (as I can with the Data-Wheel), but that doesn't work too.

Does anybody know this problem? Please help! What setting must be done to use the slider?

thanks.
chabo