T400 USB issue

[csfreelancer]

I'm having a strange issue at work with many of our t400s when a usb device, usually a mouse, is attached. After a while the pointer will scroll to the left on its own and not respond. Occasionally a printer will print documents backwards. This problem occurs on all usb ports, sometimes simultaniously. We're running an omni build of xp, I don't know if this has any bearing.
Thanks