Using “Designed for …” hardware with Linux was always a pain. Vendor support suggests to “use software from CD”, and check if card is properly installed “by clicking on My Computer, and then …”. And then I explained that I’m running Linux. I was told that Linux is not supported and card is not prepared to work with it.
I have tested some bttv “card=” parameter options and I realized that none of them works properly. With most of them I was unable to tune to any TV station, with other there was no sound and radio does not work with any of them.