I've got a Hauppauge PVR 150 TV-card, this card uses the ivtv driver.
Since the ivtv driver is in the kernel (video4linux), oa with Sabayon 3.4b3 I couldn't emerge ivtv....
The solution to get the tv-tune and utils is to get the sources from http://ivtvdriver.org/index.php/Main_Page
build only the sources in iv-tune an util directory and put the executables in /usr/local/bin or were you like it. So you can tune with iv-tune and watch (mplayer) or record (cat) raw stream through /dev/video0
The ordinary v4l programs can't handle this card yet.
Kdetv can handle the tuner but not the mpeg2 output, it also pushed the card in a very low resolution and turn the sound off. Xawtv an tvtime can't handle this card.
I also recompiled the kernel with all v4l an sounddevices on because I'll get no sound, but don't know if this is necessarily because the no sound issue can also be caused by kdetv.