shaders produce problems on aome nvidia gpus. my radeon works all out, but when i want to show it a friend with a geforce (fx5600 for example) the render to texture shows up, but with no shader on it. using shaders on such things is really cool:)
i found out that simply passing the vertexshader by mov oT0,v7 ... and only doing some manipulations like negating it works on nvidias too, but if you want mor, say you use normals in the vs nvidias go down