Manually compiling the latest alsa-driver-1.0.19 (./configure; make; sudo make install) fixes the problem, so it is indeed a problem with the version of ALSA we ship in hardy.
Manually compiling the latest alsa-driver-1.0.19 (./configure; make; sudo make install) fixes the problem, so it is indeed a problem with the version of ALSA we ship in hardy.