SetCubeMode not working?

I try to test the different CubeModes with my little mesh here but it doesn't seem to change anything.

Yes I do have a cubemap loaded and applied to the entity(mesh) together with a normal colourtexture.
It looks fine with it's Specular mode but I want to try the different modes and when setting the command:

SetCubeMode Env,2 (where Env is my cubemap-texture) nothing actually changes. I try to apply it again on the mesh but nothing changes.

Anyone encounter similar problems?

Did you try this example:
http://www.blitzbasic.com/b3ddocs/command.php?name=SetCubeMode&ref=goto

I will try it immidiatly. Where can I find those media-files?

You should already have them. Type SetCubeMode in the IDE, double tap F1 to bring up its help topic then you can click on "Example" and the code should be compilable.