Synaptics Touchpad

Open this file: 

$ sudo nano /etc/hal/fdi/policy/shmconfig.fdi

Then copy these lines and drop them into the empty file you just created. 

<?xml version="1.0" encoding="UTF-8"?>
<deviceinfo version="0.2">
  <device>
    <match key="input.x11_driver" string="synaptics">
      <merge key="input.x11_options.SHMConfig" type="string">True</merge>
    </match>
  </device>
</deviceinfo>

This is a link to the source of the above.