Hmm, this is very interesting. This confirms that what I suspected is causing the problem.

The numbers mean Average, Notable (i.e. quite a bit larger than expected), maXimum time in milliseconds that the audio_write kernel call is taking. 232 is bad. :-(

The maximum is never reset so if it happens you might like to reboot in order to do so.

--
Mike Crowe
I may not be speaking on behalf of empeg above :-)