No HDMI audio in Debian Wheezy with driver version 295.33 on GTX560M

[Penguincoder]

I recently purchased a new laptop and installed Debian Wheezy on it. I installed the Nvidia driver the 'Debian way' via the instructions at http://wiki.debian.org/NvidiaGraphic...Installation-1 . However I have no HDMI sound output with my Nvidia card. Video output over HDMI works, although the colors are 'muted' and washed out.

Distro: Debian Wheezy
Kernel: Linux sagerdeb 3.2.0-2-amd64 #1 SMP Tue Mar 20 18:36:37 UTC 2012 x86_64 GNU/Linux
Card: Nvidia GTX560M
Driver: 295.33

Output Device: Onkyo HT-R680 (7.1ch)

aplay -l

**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC892 Digital [ALC892 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 7: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 8: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 9: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

speaker-test -c 2 -r 48000 -D hw:1,7

Plays white noise on my first two speakers for the connected HDMI connection, but trying to pass a channel argument of 5 or 7 reports back as

Channels count (5) not available for playbacks: Invalid argument

Alsamixer for device 1 shows 4 S/PDIF controls at a volume of 00. They are not muted, although I cannot increase the volume via alsamixer (using +/-, PgDn/PgUp).

I have been through many troubleshooting steps (including the document at ftp://download.nvidia.com/XFree86/gp...ouble_shooting ) but nothing in my past month of trying has been able to successfully output audio to the Onkyo.

Seeing as the speaker test DOES at least see and manage to play to two speakers over the HDMI port, what is happening that any other audio is not able to play over the 2 to 7 channels, and what can I do to et my HDMI audio to work properly?