Banishing the Drifting Pointer

A well-known problem with Dell Latitude laptops such as the D800 concerns the mouse pointer, which can start drifting across the screen of its own accord, for no apparent reason.

The cause of the problem is the small thumbstick embedded in the keyboard. Under Windows XP, I had applied the simple fix of disabling the stick in the mouse preferences dialog, but when I upgraded my D800 to Ubuntu 9.10 the other day, the problem reappeared - and there was no handy option in System Preferences to correct the issue.

Some blogs advocate the drastic step of cutting cables inside the machine, but fortunately I came across a less scary solution in the comment to another blog entry.

Adapting this to my own system, I ended up creating a file /etc/hal/fdi/preprobe/disable.fdi containing the following:

<?xml version="1.0" encoding="UTF-8"?>
<deviceinfo version="0.2">
  <device>
    <match key="input.product" string="DualPoint Stick">
      <merge key="info.ignore" type="bool">true</merge>
    </match>
  </device>
</deviceinfo>