Comment 61 for bug 198453

@bod_: Alsa is a part of the kernel that provides for sound drivers and direct access to sound hardware. Pulseaudio is a sound server. Two completely different things.

I can confirm this bug (especially Flash plugin seems to be devoid of sound when running Rhythmbox, for example). When using the /etc/asound.conf workaround mentioned above, I can at least use rhythmbox and have Gnome sound at the same time.

By itself, to me (but I am a layman in this subject), this seems like a conflict between apps that use Pulse and apps that use Alsa directly. The Alsa apps either get locked out by Pulse or lock Pulse out. If that is so, this is not a bug, but simply the way things work and a design fault on the side of the Ubuntu Hardy architects: it is possible to work around this, at least partially. For afaik, Fedora has been doing Pulseaudio for some time now, and I do not remember having trouble with Pulseaudio there. Devs might want to check out the way Fedora has tackled this problem. They must have a workaround for apps that want to use Alsa directly too. Don't know about Skype though. Hardly use it.