When kdemultimedia is installed, it apparently does some sound/ALSA related config tweaks at KDE startup. The result is that everything *looks* fine in various mixer apps (kmix, gkrellm-volume, alsamixer -> no muting, sound levels up and sane etc), but there's no sound. I will attach a diff about what happens to asound.state: asound.state.good is my working configuration, and asound.state.bad is the one after starting up KDE when kdemultimedia is installed. Why everything looks fine in alsamixer etc, beats me. The diff clearly shows that "Musix Playback Volume" has been set to 0 by something, but that is not shown in the mixer apps. Trying to change the sound levels from kmix or alsamixer has no effect. In case it matters, I have an SB Audigy. Oh, and removing kdemultimedia works around this; without it no spurious config changes happen and sound continues to work fine.
Created attachment 100901 [details] Spurious asound.state changes made by kdemultimedia
Correction: the "Music Playback Volume" change to 0 has been made only to the left channel, and is shown correctly in alsamixer. However, the issue remains, changing that in alsamixer has no effect and the only way I've found how to get sound working again is to remove kdemultimedia.
Could you please try to reproduce with fc3 or rawhide? If the bug still persists, i will look into it. Thanks.
The box where this happened doesn't really exist any more, so I cannot test with the exact same configuration. However, the FC3 and rawhide systems I have access to are pretty much similar to that one, and the problem seems to be gone. I'm afraid (heh) I won't be able to reproduce this any more, so closing, assuming fixed in current releases.