In Sound Preferences, Applications tab, if I move the volume slider for a specific application all the way to the left, the Mute checkbox for Audacious activates, but then doesn't de-activate when I move the Audacious slider back to the right. This is not intuitive; I would expect the volume to go back up. I'm pretty sure the right solution is not to turn the Mute checkbox on, since that's not an intuitive result of adjusting the volume. It might be OK if it automatically comes on only when the volume slider is all the way to the left, but I don't know if the system would be able to tell the difference between having turned the Mute attribute on manually vs. automatically due to sliding. Version: pulseaudio-0.9.15-17.fc11.i586
I see the same problem with Fedora 12 (pulseaudio-0.9.19-1.fc12.i686 from Rawhide desktop-i386-20091024.19.iso running from LiveUSB).
Upstream design decision.