Making the cursor move in Ubuntu while my thumb rests on the trackpad

Question

Just installed Ubuntu 13.04 on a 2012 Macbook Air (4,2), with good results. I've turned on all of the trackpad gestures I want via synclient, except for one: I almost always move the cursor with my index finger, while resting my thumb on the very bottom of the trackpad. This produced totally normal behaviour in OS X, but it results in no movement at all in Ubuntu.

Is enabling this just turning on one more of the synclient options, or is there something else I'm missing?

Answer 1

This is a confirmed bug in the xserver-xorg-input-synaptics driver -- add your vote if you're affected! There is another trackpad driver (xf86-input-mtrack) that advertises support for ignoring likely idle thumb touches and any upwards-moving touches at the bottom edge of the trackpad, but it appears to depend upon experimental xorg input ABIs.