Asus G73Jw gtx 460m secondary display issues

Hey all. Recently new owner of this amazing laptop. I'm very pleased with its performance so far, my only problem being with using a second display.
I'm currently connected through an Onkyo receiver and all is fine when the laptop is displaying the second screen, until I go full screen with applications like wmp
Once in full screen the screen will go black for a second or two then change resolution and color settings on me.
cant seem to place this issue and some assistance would be greatly appreciated.

Another issue I appear to be having is setting up my surround sound through my receiver. It will drop audio while I'm testing the speaker configuration and the receiver seems to be picking up different signals from the laptop while it is doing this. It seems like it is trying to switch between different listening modes but i am unsure.
Also while unpausing a video i lose audio for a few seconds before it kicks back in.

Again if you could point me in a proper direction it would be greatly appreciated, as I'm mainly using this laptop as a desktop I would like the Secondary display and surround sound to be flawless.

 

all fixed. the issues was that the grapphics card wasn't streaming full screen content to the second screen. Found the option in the Nvidia control panel.