First I'll say that this could very likely be the x-axis encoder.
The kit disc works astoundingly on the y axis; it will move the entire height of the screen in one finger travel. And the original disc is just fine on the x axis....it just doesn't have the resolution of the kit disc.
But with the booster kit disc on the x axis, the mouse arrow moves only in small judders. If I put the encoder a little closer or farther, it hardly reads.
This is a Happ trackball
Does anyone have any ideas or advice?