I have the same (or similar) issue - when I try to playback, I hear just few miliseconds of sound, then one loud click and then is all silent. Sometimes it clicks immediately.
When I try the same with Audacity 2.0.3 then everything is ok.
After this loud click, it seems that soundcard is stucked, because for playing again I have to try to play i.e. wav file through QuickTime twice (first time it just clicks as well as in Audacity 2.0.4 and 2.0.5, second time start to play).