Please help me. I tried to write a simple bump mapping demo with CG shaders. I used: OpenGL, C#, TAO framework (with MS Visual Studio 2005). When the program reach this line (in runtime): Gl.glActiveTextureARB(Gl.GL_TEXTURE0_ARB); I get this error: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt." Why ??? (i tried not to use cg shaders, and i received the same message...) If the source code can help, i can upload it.