This is the http://www.jpct.net/wiki/index.php/Advanced_example for the code and in my computer the sun light is invisible or broke the terrain in two parts:

I'm starting with the JPCT, but when I run the "advanced example" available on the site, the sun appears on the side like a part of the floor, I saw that this example fuciona on other computers. I use windows XP and the other computers use Windows 7, I hope you can help me.