I cannot seem to get skydome to work. I have selected it in the 3d-cube options for it to be on and gotten a background for it and chose it. I restarted but still nothing, just a black background. Any idea?

CCSM>> desktop cube >> Appearance >>skydome

and in Skydome image, try different images in png format first
and see if it works. I found images with 1024x768 size to work all the time in my laptop.