I'm running Ubuntu 12.04 with a working auto-hide launcher bar, i.e., the touch to the left of the screen revealed the menu. It has stopped working perhaps the result of an automatic update. I have tried setting the sensitivity to no avail. I have turned off the auto-hide feature so that I have access to the bar.
There's a workaround for this problem posted by Doug McMahon here:
From the comment:
To be a bit more verbose - for those looking for a tmp workaround till fixed - if no current
/etc/X11/xorg.confthen create one with this in it
Section "Device" Identifier "NVIDIA GeForce" Driver "nvidia" Option "ConstrainCursor" "no" EndSection
If there already is an xorg.conf with a device section then just add a line line in the section
Option ConstrainCursor" "no"