http://bugs.winehq.org/show_bug.cgi?id=28622
--- Comment #40 from Jörg Höhle hoehle@users.sourceforge.net 2012-03-06 07:58:16 CST --- BTW, I conducted the following experiment: I had hw:0 locked by speaker-test, so PulseAudio would not be able to grab it (PA0.9.x in Ubuntu Lucid). Nevertheless, the render test had PulseAudio open and write almost a buffer full of samples. Then padding remained frozen at the same value. There never was any error message. I feel Gilboa's situation is somewhat similar, except that underruns are continuously signaled. Neither does PA manage to play audio, nor does it manage to return error codes that would reveal its trouble.
The return NULL hack before snd_config_update() is the last thing to do before going to PA's bugzilla with this issue.