I like to watch some shows from german TV channel pro7, but unfortunately their site depends on Move Media Player, which only support Windows.

In the windows version of Firefox (started from wine) you can install Move Media Player without problems, you can also start the video but there is only sound, no video (just black).

I found a workaround, though. Go to the site where you want to watch the video. Then, before it has begun playing, go to another tab in your browser. When you hear the sound of the video you want to watch, change back to the first tab and you should have video, too!