Track pad setting in lion

I recently upgraded both my 2011 MBP and my 2010 MBA
to lion at the same time..

I noticed on the MBP in the track pad settings i had the option for
the 3 finger drag.

The MBA does not have this option..???

I've attached screen shots.

i upgraded them at the the same time so the both have the same version.
has anyone ever seen this?? or have an answer,
cuz i use this feature all the time..

Thanks

It's the hardware. My 08 mbp wouldn't have the 3 finger drag either.

track pad

That doesn't make sense
the track pad has 3 finger
and 4 finger commands that work, like swipe, mission control, and expose.


so the hardware and drivers are there to see multi finger gestures,
just not this particular option???