I have an installed version of hardy desktop edition (installed from the alternate cd because I'm running software RAID).

I just added a Hauppauge PVR-150 in the box. It is automatically functionnal and I can play video using vlc or mplayer using
mplayer /dev/video0
(I forget the command for VLC).

However, whatever the player, I get the image without a problem, but the sound is so low that I have to max my speaker output and even then, I have more background noise comming from the PVR than any other interresting sound.

By the way, I tried the card in my Windows PC and it worked ok (even if it was more difficult to install the drivers and softwares than it usually is with Linux)