Q I have Ubuntu 7.04 Feisty Fawn installed on a Sony VAIO VGN-FJ250P laptop. I'm satisfied with almost all aspects of this distro, with just one or two niggling problems. The one I've been putting the most effort into recently regards OpenGL. It seems not to work on this Linux system. I know that it's supported by the Intel video chipset, because I dual boot with Windows XP Pro, and OpenGL applications run fine there. One of the affected applications is Planet Penguin Racer, which ran fine on the Live CD but doesn't run when installed on the hard drive. Attempting to run it from the menu produces nothing, while attempting to run it from the command line in a terminal produces the following error message:
'*** ppracer error: Couldn't initialize video: Couldn't find matching GLX visual (Success) Segmentation fault (core dumped)'
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A The good news is that OpenGL works on your hardware with the Live CD, so the hardware is supported and the software present on the CD. This is a configuration problem, almost certainly in xorg.conf, caused by the installer not setting up your graphics card correctly. Boot from the Live CD, mount one of your hard disk partitions or a USB pen drive, and copy /etc/X11/xorg.conf to it. Now boot from your hard disk and compare its copy of xorg.conf with the one you just saved. The most likely cause is that your hard disk version of the file is either using the wrong driver (the Driver line in the Device section of the file) or that the GLX module isn't being loaded. Before you make any changes to this file, save a backup copy: you don't want to make things worse. The correct driver for your hardware should be i810, although using whatever is in the Live CD version of the file will work. The GLX module is loaded by including this line in the module section of xorg.conf:
Load "glx"
If both of these are set correctly and OpenGL doesn't work, you could work through the two files looking for differences and trying to identify which one is the cause. Or you could simply replace the installed file with the Live CD version, knowing it will work.