Comment 1 for bug 293700

xorg.conf no longer has an entry for the DarU1's synaptic touchpad.
In previous versions of Ubuntu, one would add...
"SHMConfig" "true"
...to the xorg.conf.

Now this is done by modifying this file...
/usr/share/hal/fdi/policy/20thirdparty/11-x11-synaptics.fdi

...by adding this line...
<merge key="input.x11_options.SHMConfig" type="string">On</merge>

...to the section that starts with...
<match key="info.product" contains="Synaptics TouchPad">

More complete instructions are here...
http://ubuntuforums.org/showpost.php?p=6077309&postcount=121

This fix will be added to the System76 Driver.