HTML5 Audio: Music does not stop even after navigating away from the website

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Javascript

Mobile

iPhone

audio

, +

I'm making a mobile game using HTML5. There is a background music that runs during the gameplay and should ideally stop once I navigate to another page... The logic works properly on older iPhones and android.
However, on iPhone 4 and iPads the music doesn't stop and continues to play (even when I navigate to another website) until the browser is closed.
Of course there is a call

music_var.pause()

function in the code as well as the unload handler... but this simply doesn't seem to work.
Any ideas on what is happening here?