Last year a co-worker frantically came over to tell me that text was disappearing from her computer screen. I walked over to her desk and watched as she began t

Last year a co-worker frantically came over to tell me that text was disappearing from her computer screen. I walked over to her desk and watched as she began to type an email. Sure enough, the characters she entered went away one at a time. I glanced down at the desk and gently lifted a headset that was resting on the "delete" key of the keyboard.