I am noticing a slight milisecond adjustment on the multitouch when it on or off. I was going that perhaps, macmee thinks he taps 2 fingers at the same time, but there is a slight delay, which is just enough to no register with him.
Personally I enable this feature for improved tracking not fixing the multii-touch.
Its a simple check box, so it doesn't hurt trying, is what I was going with. All I can think beside that, is that macmee is not typing hard enough (not suggesting that you need tap hard).