I have a new ATI graphics card which gave me black screen with HDR enabled.
The only way I found to fix it is to enable 3.0 shaders in Oblivion.ini and force 3.0 shaders.
Forcing 3.0 shaders was necessary for it to work. The shaderpackage 02, in my case, was replaced by 19.
Should I take any precaution while installing Detailed Terrain? Is it OK to apply the mod with the tweaked shaders?