I upgraded to Kubutu Hardy Heron recently, and found that it’s easier to get sound working on this lappy now.

You still need to use module-assistant to install alsa from source, and I’m finding that I still need to have

options snd-hda-intel index=0 probe_mask=1 model=benq

in my /etc/modprobe.d/alsa-base.

However, now sound seems to be more stable and you can control both the headphone and speaker levels independently in your mixer — the “Front” channel for the speakers, the “Headphone” for the headphones.