Intermittent Problem - Laptop won't boot when docked

Hi,

A client of mine keeps having an intermittent problem where, when his Latitude D820 is docked, it fails to boot, freezing on the Dell Splash Screen where the loading progress bar is displayed.

Its intermittent as the problem has now gone away, but yesterday, neither his D820, nor my D830 would boot on his docking station.

It happened a couple of months ago, and he docked his D820 on my docking station, where it also failed to boot, but then docking it on his worked.

Yesterday, I took a 5 minute walk to his lab, tried my D830 on his docking station and it wouldn't boot, and neither would his D820, then somewhere between me taking his docking station back with me on the 5 minute walk, plugging it in in my workroom, the problem was resolved.

Can anyone shed some light on whats happening here? And maybe a possible fix to solve this if it happens again in the future, and perhaps a reason as to why this is happening? I have a feeling it is something the user is doing, like undocking without pressing the prepare to undock button. He also mentioned the touchpad and certain keys not working after his laptop went into standby prior to this problem.

Any help would be very grateful! Both laptops are running XP Professional SP2.

Regards,

Alex