[Udo]

> - I have to kill Firefox in order to make sound work in VLC... wtf?

Sadly, that's not a Ubuntu-specific problem. Recently, I had to borrow an openSuSE box for a few days and this was basically the first time I used client-side Linux in ten years and I was appalled. One of the many many annoyances was that only one program could use audio at a time. Like you described, I had to close Firefox after playing a Youtube vid, just to open VLC in a functional state (and this was on KDE I believe).

After all these years of not looking at the state of GUI on Linux I was extremely surprised by how little advancement happened in this time. I don't say this to flame, but I'd be really interested how things ended up in this sad state. The overall "experience" is just a nightmare.