If your using jPlayer and your doing something like this:
($jplayer
.jPlayer('clearMedia')
.jPlayer('setMedia', {
mp3: '/some.mp3'
})
.jPlayer('play')
);
... and maybe you've looked at the android logs and seen "Attempt to call getDuration without a valid mediaplayer". The problem is the 'play' command. You should move the play command to an event.