2.2-beta1 removes alsa-ng plugin. The only remaining choice, alsa-gapless,
fails to initialise with alsa-plugins-pulseaudio + pulseaudio.

[...]

Audacious 2.2-alpha2 defaults to alsa-ng output plugin, which fails
to work with PulseAudio (F-11). Switching to the only other choice, the
experimental alsa-gapless plugin, doesn't work either. There is no
pulseaudio plugin anymore.

[...]

2009-09-20:
With alsa-gapless output plugin in 2.2-alpha1 on Fedora 11 the poll()
playback freezes have returned for me.

[...]

$ md5sum audacious-plugins-2.2-alpha1.tgz 
172ea9937709f2dcb73fd4a93355d6df  audacious-plugins-2.2-alpha1.tgz

contains a new 3rd generation "alsa-gapless" output plugin, which
may or may not fix some of the problems with playback. "alsa-ng" seems
to be quite susceptible to underruns (snd_pcm_writei() -EPIPE rv),
especially together with alsa-plugins-pulseaudio + PulseAudio.