I’m not sure if the problem occurs if connected directly to the without USB hub. I have it plug directly into the Pluggable powered USB adapter. It’s a little bit too far away to get to the back of my PC at the moment to plug it in directly to its USB ports. If I turn the tracker off with the system tray Tobii icon, it’s only the center six LED lights that remain on. The IR LED lights on either end turn themselves off properly. The Tobii USB cable is really quite short. I’ll double check and get back to you.