Using the demo at:
Note: Demo, currently, has a few misc. bugs.
In IE9, Image Viewer continues to play audio after closing/navigating Image Viewer, if the current item contains an iframe in providers.container
1. Click an item that contains a media player embedded in an <iframe>. I used the blue Op'nWorks Liferay one.
2. Play the video.
3(a). While the video is playing, either close the overlay. (Audio continues to play in background.)
3(b). Click the next or prev arrow. (Audio continues to play in background.)