I have a fresh install of ubuntu 12.10 for a home theater PC. It is connected to my plasma tv over hdmi. I mostly interact with the computer over VNC when I need to change settings, etc. The problem is, if the tv/receiver is turned off, ubuntu does not detect a display device and I get an error stating so and something about low-graphics mode. I would like ubuntu to just ignore this and still start up at the right resolution without complaining. Is this possible? How do I do it?