Don't Look at the Light!
Customer: "My mouse doesn't work any more."
Tech Support: "Is it an optical or ball mouse?"
Customer: "Huh?"
Tech Support: "Does it have a ball or light?"
Customer: "It has an light on top."
Tech Support: "On top?"
Customer: "Yeah. It was underneath before, but it looks better when it's on top."
Tech Support: "Ok, try turning it around so the light points down on the desk."
Customer: "Oh! It works!"