After upgrading from 11.10 to 12.04 on a Thinkpad W520 system all mouse/pointer input devices (on this machine that includes the so-called 'TrackPoint pointing stick', a 'TouchPad', and, what I actually use, a generic wireless USB mouse) fail to work properly if the laptop is in it's docking station. The pointer is 'stuck' along the left edge of the screen. The pointer can be moved vertically, but not horizontally. If the laptop is removed from it's docking station then 'mouse' devices appear to function normally.
Examining /etc/X11/xorg.conf I see that the 'upgrade-manager' has commented out all the traditional configuration for the mouse (and keyboard) with a pointer to /etc/default/console-setup. Looking there, I find nothing that seems to refer to mouse configuration.
Trolling /var/logs and dmesg for complaints about 'mouse' doesn't turn up anything.
In previous Ubuntu releases, I have not needed to do anything for the docking station to work.
FWIW, my normal set up is the laptop in a docking station with two ViewSonic VX2450wm LED monitors in a 'twinview' mode, and a wireless USB keyboard. The laptop itself has a Nvidia Quadro 1000M graphics device. None of the mouse devices are attached to the docking station.
I'm not sure how or why the docking station relates to mouse input, but it clearly has some impact.
This seems like something way too basic to just stop working on an upgrade, but I'm at a loss to see what the upgrade has messed up. Any suggestions of what to look at would be very much appreciated.