[CentOS] Audio weirdness on CentOS 6.2 with flash?

Hi List,
I have an ASUS G73S laptop with our favorite OS installed and all 
up-to-date.
Sound has always "just worked"
When I use the Preferences>Sound app I can setup the hardware, input, 
output and was overall very impressed.
One can check each speaker and the laptop has a front left and right and 
also has a bass speaker which seems to be connected to the left rear.

The various players seem to work fine e.g mplayer, JuK, VLC media player.

Recently I wanted to play a movie off the internet and so out came Firefox.
Imagine my surprise as I hear only the background music from the rear 
channel - the front left and right appear to have disappeared.

When I plug in some headphones, it seems that the phones only pick up 
right rear and left rear - front left and right are gone (laptop 
speakers are muted due to headphones being plugged in)

So one cannot listen to audio from internet via flash player........

I have the high definition digital audio disabled as I understand this 
is for the HDMI audio system which I have not played with.

I think alsa and pulse audio are installed.
rpm -qa |grep pulse
pulseaudio-module-gconf-0.9.21-13.el6.x86_64
pulseaudio-utils-0.9.21-13.el6.i686
pulseaudio-module-bluetooth-0.9.21-13.el6.x86_64
pulseaudio-0.9.21-13.el6.x86_64
pulseaudio-libs-glib2-0.9.21-13.el6.i686
pulseaudio-libs-glib2-0.9.21-13.el6.x86_64
pulseaudio-module-x11-0.9.21-13.el6.x86_64
kde-settings-pulseaudio-4.3.1-1.el6.centos.noarch
pulseaudio-gdm-hooks-0.9.21-13.el6.x86_64
pulseaudio-esound-compat-0.9.21-13.el6.x86_64
alsa-plugins-pulseaudio-1.0.21-3.el6.i686
pulseaudio-libs-0.9.21-13.el6.i686
alsa-plugins-pulseaudio-1.0.21-3.el6.x86_64
fluxbox-pulseaudio-1.1.1-5.el6.noarch
pulseaudio-libs-0.9.21-13.el6.x86_64
pulseaudio-libs-zeroconf-0.9.21-13.el6.x86_64
pulseaudio-utils-0.9.21-13.el6.x86_64

rpm -qa |grep alsa
alsa-plugins-oss-1.0.21-3.el6.x86_64
alsa-utils-1.0.21-3.el6.x86_64
alsa-plugins-samplerate-1.0.21-3.el6.i686
alsa-plugins-vdownmix-1.0.21-3.el6.x86_64
alsa-plugins-speex-1.0.21-3.el6.x86_64
alsa-plugins-usbstream-1.0.21-3.el6.i686
alsa-lib-1.0.22-3.el6.i686
kmod-alsa-1.0.24-1.el6.elrepo.x86_64
alsamixergui-0.9.0-0.9.rc2.el6.x86_64
alsa-lib-1.0.22-3.el6.x86_64
alsa-plugins-upmix-1.0.21-3.el6.x86_64
alsa-plugins-usbstream-1.0.21-3.el6.x86_64
alsa-plugins-upmix-1.0.21-3.el6.i686
alsa-plugins-pulseaudio-1.0.21-3.el6.i686
alsa-plugins-samplerate-1.0.21-3.el6.x86_64
alsa-plugins-pulseaudio-1.0.21-3.el6.x86_64
alsa-plugins-vdownmix-1.0.21-3.el6.i686
alsa-plugins-speex-1.0.21-3.el6.i686
alsa-plugins-oss-1.0.21-3.el6.i686


Some stats on the machine:

cat /proc/asound/version
Advanced Linux Sound Architecture Driver Version 1.0.24.
Compiled on Apr 29 2011 for kernel 2.6.32-71.el6.x86_64 (SMP).

cat /proc/asound/cards
  0 [PCH            ]: HDA-Intel - HDA Intel PCH
                       HDA Intel PCH at 0xf6a00000 irq 35
  1 [NVidia         ]: HDA-Intel - HDA NVidia
                       HDA NVidia at 0xf4080000 irq 17

cat /proc/asound/devices
   1:        : sequencer
   2: [ 0- 1]: digital audio playback
   3: [ 0- 0]: digital audio playback
   4: [ 0- 0]: digital audio capture
   5: [ 0- 0]: hardware dependent
   6: [ 0]   : control
   7: [ 1- 9]: digital audio playback
   8: [ 1- 8]: digital audio playback
   9: [ 1- 7]: digital audio playback
  10: [ 1- 3]: digital audio playback
  11: [ 1- 3]: hardware dependent
  12: [ 1- 2]: hardware dependent
  13: [ 1- 1]: hardware dependent
  14: [ 1- 0]: hardware dependent
  15: [ 1]   : control
  33:        : timer

cat /proc/asound/pcm
00-00: ALC269VB Analog : ALC269VB Analog : playback 1 : capture 1
00-01: ALC269VB Digital : ALC269VB Digital : playback 1
01-03: HDMI 0 : HDMI 0 : playback 1
01-07: HDMI 0 : HDMI 0 : playback 1
01-08: HDMI 0 : HDMI 0 : playback 1
01-09: HDMI 0 : HDMI 0 : playback 1

lsmod |grep snd
snd_seq_dummy           1846  0
snd_hda_codec_hdmi     24897  4
snd_hda_codec_realtek   324530  1
snd_hda_intel          25565  2
snd_hda_codec          96476  3 
snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel
snd_hwdep               6874  1 snd_hda_codec
snd_seq                57357  1 snd_seq_dummy
snd_seq_device          6882  2 snd_seq_dummy,snd_seq
snd_pcm                88945  3 
snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_timer              23087  2 snd_seq,snd_pcm
snd                    73879  14 
snd_seq_dummy,snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_seq,snd_seq_device,snd_pcm,snd_timer
soundcore               8086  1 snd
snd_page_alloc          8692  2 snd_hda_intel,snd_pcm

sudo lspci -vvv
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset 
Family High Definition Audio Controller (rev 05)
     Subsystem: ASUSTeK Computer Inc. Device 1a13
     Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- 
Stepping- SERR- FastB2B- DisINTx+
     Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- 
<TAbort- <MAbort- >SERR- <PERR- INTx-
     Latency: 0, Cache Line Size: 64 bytes
     Interrupt: pin A routed to IRQ 35
     Region 0: Memory at f6a00000 (64-bit, non-prefetchable) [size=16K]
     Capabilities: [50] Power Management version 2
         Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA 
PME(D0+,D1-,D2-,D3hot+,D3cold+)
         Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
     Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
         Address: 00000000fee04000  Data: 4064
     Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, 
MSI 00
         DevCap:    MaxPayload 128 bytes, PhantFunc 0, Latency L0s 
<64ns, L1 <1us
             ExtTag- RBE- FLReset+
         DevCtl:    Report errors: Correctable- Non-Fatal- Fatal- 
Unsupported-
             RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
             MaxPayload 128 bytes, MaxReadReq 128 bytes
         DevSta:    CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ 
TransPend-
         LnkCap:    Port #0, Speed unknown, Width x0, ASPM unknown, 
Latency L0 <64ns, L1 <1us
             ClockPM- Surprise- LLActRep- BwNot-
         LnkCtl:    ASPM Disabled; Disabled- Retrain- CommClk-
             ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
         LnkSta:    Speed unknown, Width x0, TrErr- Train- SlotClk- 
DLActive- BWMgmt- ABWMgmt-
     Capabilities: [100] Virtual Channel <?>
     Capabilities: [130] Root Complex Link <?>
     Kernel driver in use: HDA Intel
     Kernel modules: snd-hda-intel

01:00.1 Audio device: nVidia Corporation GF106 High Definition Audio 
Controller (rev a1)
     Subsystem: ASUSTeK Computer Inc. Device 2048
     Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- 
Stepping- SERR- FastB2B- DisINTx-
     Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- 
<TAbort- <MAbort- >SERR- <PERR- INTx-
     Latency: 0, Cache Line Size: 64 bytes
     Interrupt: pin B routed to IRQ 17
     Region 0: Memory at f4080000 (32-bit, non-prefetchable) [size=16K]
     Capabilities: [60] Power Management version 3
         Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA 
PME(D0-,D1-,D2-,D3hot-,D3cold-)
         Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
     Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
         Address: 0000000000000000  Data: 0000
     Capabilities: [78] Express (v2) Endpoint, MSI 00
         DevCap:    MaxPayload 128 bytes, PhantFunc 0, Latency L0s <4us, 
L1 <64us
             ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
         DevCtl:    Report errors: Correctable- Non-Fatal- Fatal- 
Unsupported-
             RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
             MaxPayload 128 bytes, MaxReadReq 512 bytes
         DevSta:    CorrErr+ UncorrErr- FatalErr- UnsuppReq- AuxPwr- 
TransPend-
         LnkCap:    Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, 
Latency L0 <256ns, L1 <4us
             ClockPM+ Surprise- LLActRep- BwNot-
         LnkCtl:    ASPM Disabled; RCB 128 bytes Disabled- Retrain- CommClk-
             ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-
         LnkSta:    Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ 
DLActive- BWMgmt- ABWMgmt-
         DevCap2: Completion Timeout: Not Supported, TimeoutDis+
         DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-
         LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- 
SpeedDis-, Selectable De-emphasis: -6dB
              Transmit Margin: Normal Operating Range, 
EnterModifiedCompliance- ComplianceSOS-
              Compliance De-emphasis: -6dB
         LnkSta2: Current De-emphasis Level: -6dB
     Kernel driver in use: HDA Intel
     Kernel modules: snd-hda-intel

Not sure what other info can be of help.
Anyone else have this front / back swap issue?
Anyone have any ideas why no front channel audio output on flash/firefox??
What if anything allows these various audio channels to connect / cross 
connect?

TIA for any suggested reading - my google foo has failed to locate 
anything recent that might relate to CentOS 6.