On Dell XPS GenII Laptop, 2ghz 2 gig ram, Nvidia 6800 Ultra, Dual boot win XP and Ubuntu 8.10, alsa sound was working fine for about 4 years.

the sound works fine in Win XP.

the sound works fine in ubuntu when veiwing meta files, Youtube videos ect:

when watching digital animated movies using Totem, I get background music just fine but no voice. standard movies sound fine.

when playing games Guildwars and City of heros, and using teamspeak or Ventrillo the sound is very warbled.

It seems that only the digital sound is messed up.

I have apt-get purge removed alsa and apt-get installed it several times.

is there a file somewhere that the digital sound uses? I am thinking this file is corrupt, but it does not get updated with a fresh install of alsa.

What is the audio hardware? Sometimes you need to set a few extra parameters when you're using something like the SPDIF or AC3 output on a chip like the EMU10K; perhaps your system was set up correctly before and an 'update' or similar disabled the original configuration.