Are you using ALSA? If not, try it. If so, have you run alsaconf? Have you used alsamixer and/or amixer (they are different, and sometimes only amixer will do the job) to investigate the many different mixer settings? Are you sure the kernel module for 2.6.11 is loading properly? Or have you been through that already? You didn't mention whether this list is one of the "applicable lists" or not. :)