Docking Station Overriding Touchpad Settings

One of my network users has a Latitude C400 laptop, running Windows XP, plugged into a C/Dock II expansion station.  He's found that while he's typing, the touchpad is a real nuisance:  "Incidental" contact with the touchpad has been a factor in several of his documents getting severely messed up.  Part of the problem is that the touchpad is so sensitive that it doesn't take much contact at all for the mouse cursor to go skittering across the screen.

Since he's got two good external mice he can use (a PS/2 while docked, and a USB while undocked), he would just as soon have the touchpad disabled entirely.  So we both played with it yesterday, and found that we couldn't access the touchpad settings (via Control Panel --> Mouse, or anywhere else) while the machine was docked.

Last night the user took the laptop home, and found that while it was undocked he could get to the settings to disable the touchpad.  So he did just that, and the touchpad stayed disabled while he worked.

But when he brought the laptop back in and docked this morning, the touchpad was working again, and once again he couldn't even get to the touchpad settings.  Apparently, something in the docking station is overriding the changes he makes while he's undocked.

So my question is:  How do we prevent the docking station from overriding those settings?  Or how do we go about gaining access to the touchpad settings while the computer is docked?

It looks like it may have something to do with hardware profiles in XP.  The user tried several rounds of undock-change settings-redock (rebooting in between, of course), and he noticed that when he redocked and then rebooted, the touchpad was not enabled (i.e. it wouldn't move the mouse cursor) until Windows was almost done loading.

Any ideas would be appreciated.  Thanks in advance ...