No Sound in Fedora 17

[CptElectric]

When I try to watch Youtube videos, most of the time the sound does not work. Sometimes it does, I'm not sure why. Also, VLC audio does not work.
Can someone please help me figure out what's wrong?
When I run "play /usr/share/sounds/alsa/Front_Center.wav" no sound plays and I get an error:

ALSA lib pcm_hw.c:1466:(_snd_pcm_hw_open) Unknown field slave
play FAIL formats: can't open output file `default': snd_pcm_open error: Invalid argument

When I run 'dmesg | egrep -i "(alsa|sound)"' I get:

[   18.668170] ALSA sound/pci/hda/patch_realtek.c:1273 SKU: Nid=0x1d sku_cfg=0x40179a2d
[   18.668173] ALSA sound/pci/hda/patch_realtek.c:1275 SKU: port_connectivity=0x1
[   18.668174] ALSA sound/pci/hda/patch_realtek.c:1276 SKU: enable_pcbeep=0x1
[   18.668175] ALSA sound/pci/hda/patch_realtek.c:1277 SKU: check_sum=0x00000007
[   18.668177] ALSA sound/pci/hda/patch_realtek.c:1278 SKU: customization=0x0000009a
[   18.668178] ALSA sound/pci/hda/patch_realtek.c:1279 SKU: external_amp=0x5
[   18.668179] ALSA sound/pci/hda/patch_realtek.c:1280 SKU: platform_type=0x1
[   18.668180] ALSA sound/pci/hda/patch_realtek.c:1281 SKU: swap=0x0
[   18.668181] ALSA sound/pci/hda/patch_realtek.c:1282 SKU: override=0x1
[   18.668516] ALSA sound/pci/hda/hda_auto_parser.c:322 autoconfig: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:speaker
[   18.668518] ALSA sound/pci/hda/hda_auto_parser.c:326    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[   18.668519] ALSA sound/pci/hda/hda_auto_parser.c:330    hp_outs=1 (0x21/0x0/0x0/0x0/0x0)
[   18.668521] ALSA sound/pci/hda/hda_auto_parser.c:331    mono: mono_out=0x0
[   18.668522] ALSA sound/pci/hda/hda_auto_parser.c:335    inputs:
[   18.668523] ALSA sound/pci/hda/hda_auto_parser.c:339      Internal Mic=0x12
[   18.668525] ALSA sound/pci/hda/hda_auto_parser.c:339      Mic=0x18
[   18.669680] ALSA sound/pci/hda/patch_realtek.c:1336 realtek: No valid SSID, checking pincfg 0x40179a2d for NID 0x1d
[   18.669682] ALSA sound/pci/hda/patch_realtek.c:1352 realtek: Enabling init ASM_ID=0x9a2d CODEC_ID=10ec0269
[   18.791181] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input9
[   18.791313] input: HDA Intel PCH Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input10
[   18.791369] input: HDA Intel PCH Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input11
[ 2145.129712] ALSA sound/pci/hda/hda_intel.c:2142 Unstable LPIB (88198 >= 3528); disabling LPIB delay counting

I'd be very thankful for any knowledge about what might be the matter.