1st things first...in my honest opinion Monster
Cable for this application is a waste of money.
You wouldn't notice any difference than if you
used a nice quality cable that costs 1/2 as much.
But the problem is you are making the wrong connection.
If you are using the digital audio (optical connection),
you do not connect the left/right composite jacks
(since those are analog audio)...So here's what
you do.

#1) Connect the Yellow composite video jack from
your X-Box to your yellow DVD input on your A/V
Reciever

#2) Connect your optical cable from your X-Box
to your DVD optical input on your A/V reciever

That's all you need to do. I'm not familliar
with that reciever but you may need to set it
up to recognize the digital. Probably not though.