kwintv sound

I asked about this a while ago, but didn't receive a reply, so I'll try again. For the past couple of KDE upgrades (I'm currently at 2.2.1) the sound in KWinTV is only present when the desktop in which kwintv is located is active. When I switch desktop, the sound disappears. No other kde app that I've tried shows this behaviour, and neither does xawtv. Is anyone else seeing this, or is it a config problem on my machine? TIA Anders