I'm running 64-bit 12.10 on a Dell Latitude E6430 with the Intel graphics card (NOT Nvidia). I dock it and have it attached to two external monitors most of the time.
If I ever have both external monitors powered on when I boot the system up (while docked), the X server seems to crash and I must reboot. Currently, I have to physically turn one of the external monitors off, boot the machine, log in, wait for the desktop to fully load, then I can turn on the other external monitor and work happily.
I understand that I can't drive three monitors, but I want to disable the laptop's LCD when it is docked. Is there a way to sense that it's docked (or that the lid is closed) and disable the LCD when necessary? Obviously, I don't want to permanently disable the LCD.