On OS X, with empty playlist, pressing the play/pause key twice freezes VLC.
My laptop (MacBook Pro) has a pause/play media key. Now:
I open VLC; the interface comes up with an empty playlist. I press the pause/play key; an "Open Source" dialog comes up. I press pause/play again.
At this point, VLC is subtly frozen. I can close the dialog, and can move the VLC window around, close it, and browse through the drop-down menus. However, the VLC window does not respond to any commands; cmd-Q doesn't work, and the Quit option in the drop-down menu (along with many other options) is greyed out. I can't quit it! Nor can I do anything else to it. Even "killall VLC" doesn't work; I have to use "killall -KILL VLC" (non-catchable, non-ignorable kill) to end the process.
This also happens when I open VLC, open "Advanced Open File..." (which brings up the same "Open Source" window), and press pause/play. (The freeze does not happen when there is something in the playlist.)
This is OS X 10.6.8, running a VLC 2.0.4 nightly build from one or two nights ago. The problem also happens on VLC 2.0.3.