Mac Mini. OS-X 10.9.5 (Not Yosemite)
Audacity 2.0.5 is installed normally under /Applications. Audacity 2.0.6 and Audacity 2.0.3 are installed in “portable” folders (attached).
Audacity 2.0.3 appears to run just fine as does 2.0.6, but 2.0.5 hangs the window with the Spinning Beachball of Death and attached message. Changing focus and Force Quitting is the answer.
2.0.5 was the active, used version until the 2.0.6 install.