Had same problem on Thinkpad W520, Oneiric 64-bit, MiniDock 3 and found this post: http://ubuntuforums.org/showthread.php?t=1043568
Adding the line 'options snd-hda-intel model=thinkpad' to the end of /etc/modprobe.d/alsa-base.conf then rebooting seemed to fix the problem for me.
Had same problem on Thinkpad W520, Oneiric 64-bit, MiniDock 3 and found this post: ubuntuforums. org/showthread. php?t=1043568
http://
Adding the line 'options snd-hda-intel model=thinkpad' to the end of /etc/modprobe. d/alsa- base.conf then rebooting seemed to fix the problem for me.