I have the 15" model and i dont have that problem. I hope this doesn't sound stupid or patronising but if you place two fingers on the trackpad at the same time you will notice that the cursor doesnt move - thats if your not in a document. The new trackpad detects how many fingers u place on it to perform the scrolling action.
So if you're NOT scrolling through a document/web page and u have both fingers on the trackpad the cursor will NOT move. Could that be your problem? I noticed that I was doing that because im an idiot. 😱
Maybe just reinstall OS X and hopefully that will fix your problem.