I'm on an old LG r405 with the built in graphics card: Nvidia g86 GeForce8600 gs rev a1
Seeing as it has a VGA output, I figured that it'd be nice to use my HD screen (benq senseye g2222hdl) It works perfectly with my OSX partition, but booting up with Ubuntu doesn't work at all.
Initially when I installed 12.04 clean everything was fine, except for the screens being swapped left to right. When I swapped places in the setup application everything started going bad. The screen content was scrambled totally, I couldn't even see where the mouse was at to reboot the computer and had to hold the power button down.
If I forget to unplug the screen when booting into Ubuntu, the resolution of the Laptop screen is set really high, but as soon as I log in, the contents get scrambled again.