Yesterday I was doing this tutorial (http://www.pekaro.de/blender/water/water_tutorial.html) in Blender 2.42a. Everything worked good until I had to work with the EnvMap. I loaded the image but when I rendered it, it was all black. In the little preview box (where the image should be), it was just grey/black.
I reinstalled Blender 2.41 and the EnvMap (and the whole tutorial) worked well in this version. Is this a bug or do I have to change a(nother) setting in 2.42a?