Why is the IN USE indicator light on even after I disconnect the docking station (supplied or optional) from my VAIO computer?

• If you disconnect the docking station from your VAIO computer while the IN USE indicator light is on, the indicator light stays on.
  To turn off the IN USE indicator light, perform any of these operations.

• Disconnect the docking station from an AC power source.

• Connect the docking station to your VAIO computer again and properly disconnect it. [Details]