Comment 4 for bug 118199

actually having done a google search against launchpad

there has been a multitude of bugs reported for this dating back to dapper/edgy upgrade

bug 66637
bug 105490
bug 67437
bug 65798
and maybe
bug 48514

also
https://answers.launchpad.net/ubuntu/+question/7434
http://ubuntuforums.org/showthread.php?p=1683612
http://ubuntuforums.org/showthread.php?p=2740699

Worryingly the state varies from confirmed/undecided to confirmed/high

Scott James Remnant is working on 66637

This looks like the hidden bug from hell...;-)