the old keypad behavior gets too sensitive

I usually operate my XO with an external USB trackball, and have no problem with cursor positioning. Lately I've often needed to operate XOs (hdw early G1G1, but F11 build) with the native keypad, and I can appreciate the many complaints I have heard about using the old keypad. In my case, the keypad exhibits too much sensitivity. Whenever the humidity is low, just waving my fingers half an inch above the keypad is enough to result in cursor position movement. And the cursor jumps both as I am bringing a finger (through the air) down onto the keypad, AND when I am lifting the finger (through the air) away from the keypad. [Also, just placing a finger at the "mouse buttons" at the bottom of the keypad is often enough to cause the cursor position to change.] Leaving the keypad alone (to give it time to self-calibrate) does not seem to help. The four-finger recalibrate works, but its effect soon "wears off", and the keypad goes back to being "too sensitive" again. Are there any software parameters that I can play with, to try to "dampen" the unwanted cursor position changes that I'm seeing ? Thanks, mikus