Hi,

On 10/10/06, Peter Seebach <seebs@plethora.net> wrote:
> Both are subject to driver "fixes" for Linux, which appear to both involve
> rerouting sound, and doing something special and magical which applies only
> on the Mac hardware to control a special hardware mute feature, possibly
> related to their controls for internal vs. external speakers.

It appears that the MacBook also suffers from this problem...

http://mail-index.netbsd.org/current-users/2006/09/03/0011.html
Have you tried with that setting?

   -Marco