the tone adjustment seems to require pixel shader 2.0 in beta 3.0. this "breaks" a feature that was available in beta 2.0. I'd prefer to have HDview use pixel shader if it is present, and use the old software solution if pixel shader is not present in the graphics card..
Right, that's a known trade-off we had to make. Our old tone adjustment could get by with the DX7 fixed function pipeline. The new tone adjustment needs Pixel Shader 2.0 to do high dynamic range and color management, neither of which the old did.