glxinfo | grep OpenGL
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD TURKS
OpenGL version string: 2.1 Mesa 9.0.2
OpenGL shading language version string: 1.30
Most likely you (or the distribution that packaged it) didn't build mesa with --enable-texture-float. That's required for OpenGL 3.0 and still disabled by default because of concerns over patents.