No center audio channel on 5.1 with HDMI

I am using a single HDMI cable to my Sony A/V receiver and for some reason I am not getting sound from my center channel.  This is a problem obviously as almost all of the dialog is through the center channel.  The surround audio is fantastic but because of this problem the dialog is so quiet you can barely hear it.

When I switch the audio profile from 5.1 to stereo on the receiver it sounds fine but I lose the big sound experience.

Can anyone suggest to me why this might be occuring and what I might be able to do about it?

Thanks in advance.

Maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.

To Contact WD for Technical Support
http://support.wdc.com/contact/index.asp?lang=en

Double check the AUDIO configuration on the Hub.   It almost sounds like it’s still set to STEREO mode on the Hub.

Have you tried using a Optical Cable?  This may help, even though HDMI only may be better for you…