This system currently runs Ubuntu 7.04. The system has a PCI sound card and on motherboard sound. The sound settings default to autodetect. The result is intermittent sound. Sometimes sound works after a system boot. Sometimes it does not work.
It seems the sound cards themselves get indexed differently depending on something happening at boot time. Currently the sound card is in the zeroth position, with the on board sound in the first.
$ cat /proc/asound/cards
0 [AudioPCI ]: ENS1371 - Ensoniq AudioPCI
Ensoniq AudioPCI ENS1371 at 0xc400, irq 11
1 [nForce2 ]: NFORCE - NVidia nForce2
NVidia nForce2 with ALC650E at 0xe0001000, irq 10
As a result autodetect does not. No sound comes out of the speakers until I unplug the cord from the motherboard sound jack and plug it into the sound card jack.
A workaround for this problem is in the Sound Preferences Gnome app, System > Preferences > Sound. I manually set the sound playback, and sound now works.
Clearly this is a bug in autodetection. I should not have to rewire my sound, nor should I have to set preferences to get the sound to work regularly.
Figments of a lack of imagination