Yes, maybe thats the problem... I need Pixel Shader 1.4 for the effect. I thought if a video card does not support it, just nothing happens (no effect is shown)?! And in addition the game need DirectX 9.0c. I use Squall for sound, maybe thats another possible reason for the error...

The shader itself should not take much performance...
On my machine there is nearly no difference in FPS using the shader or not.