New WD TV Live Plus - sound issues

Hi Everyone - 

Just upgraded from a WD TV Live to a WD TV Live Plus (wanted netflix and the new remote) and I’m having some issues. 

My current setup is 

WD TV Live


HDMI Cable


Samsung 42 inch TV


Optical Audio Cable


Denon Reciever

When I tell the WD TV to use audio over HDMI and tell it to auto detect the settings, it comes up with 2 channels only! That’s the first issue. If I manually go in and select AAC, DTS, Dolby Digital, etc. -  no sound.

Then there’s the weird part. When I run some Surround sound testing files through the system, I don’t exactly get 2 channels - I get mashed up four channels - L, R, Center, and Rear. There is no RL and RR, and there is no sub channel. 

If I plug the optical audio cable directly into the reciever, and set the WD TV live to optical, then the same files have all six channels working fine. The problem is the Denon reciever is an old on and only has one optical audio port - so I can’t connect all my devices directly.

Is there any way to get this working through HDMI? I just spent a good hour online and with the machine trying to get it workign, and no dice. I’m getting desperate!

Thanks

Just did a little research - looks like the way we were running things is not quite right - and the TV is not able to passthrough a Dolby signal - not sure why i’m getting 4 channels though!

Anyway my new question is: If I were using a reciever like this one (  http://usa.denon.com/Assets/Images/products/AVR-1913/c26-B007R8U5R6-2-l.jpg ) and passing everything through HDMI, would that work? 

Thanks