This problem has arisen on Sun Blade and Linux systems and usually means that the X Server on your desktop machine does not have OpenGL support. To determine if this is the problem, type xdpyinfo on a window local to your desktop. Near the top of the resulting output is a section describing the server extensions on your system. On a Sun Blade system, you should see one named GLX. On Linux systems you should see extensions named GLX, NV-GLX, and NVIDIA-GLX. If these extensions are missing, your system administrator will have to install them for you.