   [GLSL on ATIHD4800]No matching overloaded function found texture3D
  Hello I just update my driver and attempt to run a simple volume rendering GLSL shader on my ATI using ARB_fragmentshader. It works great on nvidia HWHowever I get an incredible error: the function texture3D is apparently not define?!!! I have the same error on my HTPC with a HD4xxxx chipset...NB: All my drivers are up to date...My shader :uniform sampler3D  tex3D;uniform sampler1D  tf;void main(){vec4 col= texture3D(tex3D, gl_TexCoord[0]);gl_FragColor= texture1D(tf, col.a);}My error:FRAGMENT glCompileShader "" FAILEDFRAGMENT Shader "" infolog:Fragment shader failed to compile with the following errors:ERROR: 0:7: error(#202) No matching overloaded function found texture3DERROR: 0:7: error(#160) Cannot convert from 'const float' to 'highp 4-componentvector of float'ERROR: error(#273) 2 compilation errors.  No code generatedglLinkProgram "" FAILEDProgram "" infolog:Fragment shader(s) were not successfully compiled before glLinkProgram() was called.  Link failed.PLEASE Help me!!!!   
  vec4 col= texture3D(tex3D, gl_TexCoord[0].xyz);texture3D takes three components, you were supplying four.   ;  thanks for the advice but there's no change...it appears the keyword "texture3D" is not recognized...   