In my world setup (right bar) I can not access all the options I can as shown on the wiki on the right.
On my screen it looks like this:
For example, environment lighting, gather, indirect lighting, ambient occlusion mode (add, multiply), and the entire world tab (horizon, zenith color) are all missing.
And there is something else.
About 15 minutes ago I wanted to write this post but when I switched back to blender to look for the properties that are missing all properties where there.
So I thought 'Ok great' but now everything is missing again. And I don't know why they suddenly appeared.