Comment 2 for bug 291487

When upgrading from Hardy Heron (8.04) to Intrepid Ibex (8.10) today, I had the same problem. I use the nvidia-glx-new package with envy-ng and when the nvidia kernel module didn't automatically recompile on reboot, X launched into its failsafe environment and there was no sound (intel-8x0). Initially I didn't know what was going on because I couldn't find the sound modules in /lib/modules/2.6.25-2-386/kernel/sound (just ac97_bus.ko and soundcore.ko there).

To fix it, I symlinked /usr/src/linux-headers-2.6.25-2 to /usr/src/linux-ports-headers-2.6.25-2 and followed the instructions in the Ubuntu Forums 'Comprehensive Sound Problem Solutions Guide': http://ubuntuforums.org/showthread.php?t=205449", starting at the 'sudo module-assistant a-i alsa-source' command.