Every once in a while though, on Mac OS X it can happen that these Flash video players don't have sound anymore.
It is pretty hard to figure out why, and the solution is quite random, but on macosxhints I found a comment mentioning that it could be a sampling rate problem:
/Applications/Utilities/Audio MIDI Setup
- check the properties for Built In Output.
- It might be set to 96KHz. Change it to 44KHz and audio in Flash will return immediately.
Now, I don't know what software it is messing up that setting, but I am glad it can be fixed.
I am still wondering why the Flash player would care about MIDI settings. Obviously it's no MIDI file that is being played as movie sound there.