T60 Wont shut down in port replicator

[blacksmith]

Hi All

I am helping out my Father who has just purchased a Thinkpad T60 Model 8741-8BM with Port Replicator. Running XP Pro. When not attached to the docking station, Start Shutdown works fine. As soon as it is clicked into the replicator, Start Shutdown proceeds but stops just at the point before the monitor turns off. Only a hard reset fixes ie. hold power button down for 5 seconds or so.

Any clues?

Smithy