At the risk of sounding like a moron, and certainly not to imply that your issue is user error, I have found that all my trackpad malfunctions have been my fault.
My old laptop was so heavy that I never really took it anywhere and it was always hooked to a trackball at home, and I didn't use the trackpad.
When I got my MBP, I found that the scrolling would stop and the cursor would be jumpy. I panicked. Then I realized that I was being a dumbass. If my scrolling was jerky or stopped, it was because the tip of a third finger was dragging along the trackpad. Being more careful fixed the issue. If my cursor was stop & go, it was because the tip of a 2nd finger was dragging. Being more careful fixed that issue, too.
Can I win the newbie MBP ID10T Award of the week or something? 😛