I ran software update and my sound stopped working.
I rebooted with the old kernal (3.3.8-1) and the sound is OK.
I rebooted with the new kernal (3.4.2-1.fc16.i686.PAE) and there is no sound again.
The folowing is from /var/log/messages.
Jun 22 19:49:48 localhost pulseaudio: module-alsa-card.c: Failed to find a working profile.
Jun 22 19:49:48 localhost pulseaudio: module.c: Failed to load module "module-alsa-card" (argument: "device_id="0" name="pci-0000_00_1b.0" card_name="alsa_card.pci-0000_00_1b.0" tsched=yes ignore_dB=no card_properties="module-udev-detect.discovered=1""): initialization failed.
the folowing is from lspci.
00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 01)
I failed to find a bug in bugizilla that mached.