Dell Laptop, monitor, Dell HDTV

[blameline]

Hi,
My boss has a setup in his office, a Dell Latitude laptop, docking station, external monitor using the 7-pin connector, and HDTV with the DVI 24-pin connector. He wants to have the external monitor and HDTV as clone displays.

The problem is that the HDTV will display a picture of the screen for an instant, then disappear. The picture will flash on and off at irregular intervals. Thinking that there's a short in the cable between the docking station and HDTV, I placed another laptop into the docking station and tried to see both displays. The setup worked perfectly.

So, I believe that there's a problem with my boss's laptop, but don't know exactly what, nor how to replace it. Video card? Nvidia Software? Laptop?

Thanks for any information.
Phil