FYI, there is an issue with the IVTV driver verion 1.0.3 shipping with opensuse 11.0
Ive experienced it with my pvr150 after switching to opensuse 11.0
Basically in my situation when I change channels the sound becomes distant and with static noise. I am using the coax connection, historically its sounds like it only occured on the svideo input.
Sending this command brings the sound back on my setup, buts its a temporary fix:
v4l2-ctl --set-audio-input 0 -d /dev/video0