I have a Dell Precision m6700, and prior to that I had a Dell Latitude e6520 -- the following configuration worked for both of them.
Here's a pic of my docking station:
I use my laptop's screen (open on the dock), 2 monitors plugged into the 2 DVI ports, and 1 VGA port for a 3rd monitor. I really like this setup. It's like having 4 screens.
Recently my Precision was re-imaged, and now I can't get the VGA port to do anything for me. The DVI monitors work fine. Pulling DVI connections doesn't fix VGA, nor does having VGA alone permit it to be detected.
The video adapter is NVIDIA Quadro K3000M. The VGA monitor is just black, I can press the source button on it and it will cycle through digital/analog to no result. The cables are very snug, and nothing physically has changed in my configuration -- just the Windows re-image.
I have tried using the latest NVidia drivers, the older drivers from Dell's support site, and even beta NVidia drivers to no avail. Does anyone have any other ideas?