Allright, some heart-warming update on my side.... 

I manually uninstalled the intrepid ibex 8.10 NVIDIA 177 driver and downloaded and installed the 180.08 one from NVIDIA (pkg2.run just to be on the safe side)

Now HDMI Audio works on my HP Pavilion dv9343eu !!!!

It is even funnier, for unlike in Windows, where I must choose between my laptop's loudspeakers or the Digital Conection for Audio Output, in ubuntu with Nvidia 180.08 drivers, both my TV and my loudspeakers put out sound and their volume's are independant from each other....

I guess I should paste in a lot of specs, but I don't really know which.... here go the basic ones :

alejandro@alek-ubuntu:~$ lspci
00:00.0 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
00:00.1 RAM memory: nVidia Corporation C51 Memory Controller 0 (rev a2)
00:00.2 RAM memory: nVidia Corporation C51 Memory Controller 1 (rev a2)
00:00.3 RAM memory: nVidia Corporation C51 Memory Controller 5 (rev a2)
00:00.4 RAM memory: nVidia Corporation C51 Memory Controller 4 (rev a2)
00:00.5 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
00:00.6 RAM memory: nVidia Corporation C51 Memory Controller 3 (rev a2)
00:00.7 RAM memory: nVidia Corporation C51 Memory Controller 2 (rev a2)
00:02.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:03.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:04.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:09.0 RAM memory: nVidia Corporation MCP51 Host Bridge (rev a2)
00:0a.0 ISA bridge: nVidia Corporation MCP51 LPC Bridge (rev a3)
00:0a.1 SMBus: nVidia Corporation MCP51 SMBus (rev a3)
00:0a.3 Co-processor: nVidia Corporation MCP51 PMU (rev a3)
00:0b.0 USB Controller: nVidia Corporation MCP51 USB Controller (rev a3)
00:0b.1 USB Controller: nVidia Corporation MCP51 USB Controller (rev a3)
00:0d.0 IDE interface: nVidia Corporation MCP51 IDE (rev f1)
00:0e.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller (rev f1)
00:0f.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller (rev f1)
00:10.0 PCI bridge: nVidia Corporation MCP51 PCI Bridge (rev a2)
00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)
00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a3)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
03:00.0 Network controller: Broadcom Corporation BCM4312 802.11a/b/g (rev 01)
05:00.0 VGA compatible controller: nVidia Corporation G70 [GeForce Go 7600] (rev a1)
07:05.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller
07:05.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 19)
07:05.2 System peripheral: Ricoh Co Ltd R5C843 MMC Host Controller (rev 0a)
07:05.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 05)
07:05.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev ff)

alejandro@alek-ubuntu:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: NVidia [HDA NVidia], device 0: CONEXANT Analog [CONEXANT Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 1: Conexant Digital [Conexant Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

alejandro@alek-ubuntu:~$ aplay -L
front:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    Front speakers
surround40:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=NVidia,DEV=0
    HDA NVidia, CONEXANT Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
hdmi:CARD=NVidia,DEV=0
    HDA NVidia
    HDMI Audio Output
null
    Discard all samples (playback) or generate zero samples (capture)


Please let me know how I can provide more useful info....

P.S: I am having nonetheless some trouble with the screen resolution  using the HDMI connection.... If I use nvidia-settings and set the displays as Separate X screens, on my larger 1920x1080 TV display I only get a 1440x900 desktop space (even though the desktop background centers itself correctly)... in other words, I get black bars on the right and bottom of my TV display.  Even odder, my mouse cursor is shown when hovering over these black areas..... any ideas?