I solved the problem by covering the download button of a audio controller with a transparent div that changes the symbol of the mouse-cursor to "not-allowed".
The div blocks the activation of the download button.
Height: 50px, Width: 35px, Left: (document-right -60), Top: (same as the audio controller).
You must set the z-index style of the div above the z-index of the audio-controller.
See sapplic.com/jive66 for an example that works for chrome on win7 and on win8.
