On https://de.wikipedia.org/wiki/Wikipedia:Fragen_von_Neulingen a user reports that MediaViewer is broken in IE 8, which I can partially confirm (using the IE8-mode of an IE 9):
Clicking on any image in an article shows just a black screen. I was redirected to the image description page after a few seconds, but the reporting user seems to have no way to access the image.
Clicking "Expanded view" on an image description page shows just a black screen, too.
So please either bind the events in a way that works in IE8, too, or just disable MV in IE8.