Extended monitor trouble

I have a HP Pavilion dv6768se Notebook PC running Vista Home Premium with a NVIDIA GeForce 8400 GS card. I use the S-Video output to record PowerPoints with my set top DVD recorder and to watch Instant View NetFlix movies on the TV. Today when the Laptop was sensing the DVD recorder, The color got really messed up on the TV monitor and laptop screens. I tried resetting Display Properties and Rebooting several times with no success. I also connected to a LCD monitor. It showed colors ok, but, it had a real dark picture. When the laptop is not connected to an external monitor, it displays everything normally. My question is: Do I have a corrupt driver or a bad video card?
Thanks for any help!
mediafunfan