Please remove system-config-sound from firstboot. It's main purpose (writing ALSA config files) is mostly obsolete these days and causes more trouble than it does good. For a recent example, see this posting on the Fedora ML: https://www.redhat.com/archives/fedora-devel-list/2007-September/msg01306.html It's still good as a test tool for audio, and thus should be kept in the default install. However, I see no point anymore in showing it to the user on installation. Audio devices are these days more and more Plug-n-Play. Instead of identifying audio devices by their ALSA device indexes (that are very difficult to keep stable properly) they should be identified by device paths, such as the HAL device path (that is stable all the time). PulseAudio does this now, and GStreamer does this as well. Thus, the need for stable device indexes is no more.
This will be removed in the next build of firstboot.