Terrain bumptexture in TGE 1.5

I tried to use bumptexture in TGE 1.5 but the terrain is allways flickering. I bought the FPS Env Pack which using a bumptexture and its work fine in it's demo (i think its TGE 1.4 with lighting kit). But if i load the demo mission in TGE 1.5 it dont work in same manner. I also tried it with a clean install and the stronghold mission.

Is the terrain bumptexture broken in 1.5 - or maybe fixed in 1.51/1.52? I didnt find any informations using search and hope anybody have some informations ;)