Geforce GTX 480 Audio problems

[JohnnyE 10]

Hi

My setup

2 Monitors ( one 50" Plasma and an 22" TFT) Gtx 480

problem is if i use the 22" tft for picture and sound output over the DENON av amp 7.1 it runs correctly

if i run SOUND AND PICTURE over the DENON (Plasma tv) i wont get any sound .

if i use the headset with the plasma it works...

but i will use the 50" plasma with the 7.1 denon av amp

EVERY OTHER GAME WORKS with the NVIDIA SOUND OUTPUT and Picture output on the plasma

i tryed to start with the 22" and switch to the 50" .. it works as long as i let the 1680x1050 resolution but when i switch to the native resolution 1920x1080 the sound is off.....

drivers are up to date and everything other works without any problems...

search give no results ( one other men searchd for a solution if i search with google...)

Greets JohnnyE