Xvfb with 32 bit color

Question

For some machines this works, for some it doesn't.

Xvfb :99 -screen 0 1280x1024x32

However, on most machines this works:

Xvfb :99 -screen 0 1280x1024x24

What is the secret ingredient to getting Xvfb working with 32 bit color?

Note: I'm running this on a Karmic box.

Answer 1

I've had some success with using vnc4server instead