My personal Thinkpad W510 at home randomly has the touchpad seem unresponsive. Ive also noticed this on a bunch of other 10 upgrade units. Today i noticed on a E6420, all works well but when the mouse stops being responsive (it has the proper dell multitouch driver) all I have to do is tap the windows key and it comes back up.
Is this some form of USB power save that I might have to disable somewhere? I know both of the above models connects to a connector on the board that it considers a USB device.