I have a Dell IN2030MC 19" monitor. It’s attached through the pluggable doc to a Gateway laptop. I use the external monitor as the main display and sometimes as an extended display. It worked fine using 1600x900 (the native resolution of the display). Then I attached the display temporarily to another computer and now it will no longer support 1600 x 900, nor does windows recognize the display anymore. It calls the display “non monitor”. If I attach the display directly to the laptop it all works fine.