in the first 4 days, did you update the kernel or anything else? If an update to pulseaudio or alsa caused it, you may want to file a bug report. If the kernel was updated, then have grub boot into the original kernel. If nothing happened, copy the alsa config file (.a... something, don't remember the name) from root to your home directory, and possibly the pulseaudio one, too.
Let me get something straight. No sound is working. Anywhere. Period. I get a "One of your sound devices is malfunctioning" whenever I log into my root account through KDE. I sincerely can't remember what happened 1.5 months ago, so no info there.