I figured out the glitch in Windbringer.

  2.6 alsa crash drivers fix gentoo linux lockup shutdown sound

Ever since version 2.6.29 of the Linux kernel was released I’d been having problems with Windbringer crashing on shutdown. After triggering the system shutdown applet in Gnome X would terminate, sometimes I’d see a debug message from NetworkManager as it tried to shut down the network interfaces (and sometimes the ALSA sound drivers, oddly enough), sometimes I wouldn’t see anything. The end result, however, was that Windbringer would have to be manually powered off, thus forcing a (lengthy) file system check the next time I booted up.

  <p>The answer arrived from <a href="http://forums.gentoo.org/viewtopic-t-771275.html">this thread at the Gentoo forums</a> last night – don’t unload the sound drivers when poewring down.  You really don’t have to because there is no potential benefit or harm from not doing so.</p>   <p>To do this on a <a href="http://www.gentoo.org/">Gentoo Linux</a> machine, edit the <i>/etc/conf.d/alsasound</i> file and change the value of <b><span class="caps">UNLOAD</span>_ON_STOP</b> from “yes” to “no”.  Save the file.</p>    <p>While I can’t promise that it’ll help with the v2.6.29.x series, it does happen to work with v2.6.30.</p>