Pioneer VSX-921 multi channel AAC with WD TV Live

Hi,

I have a Pioneer VSX-921, which supports AAC audio format, according to the manual. I recently added a WD TV Live to my system, which is hooked up to the Pioneer via HDMI. Dolby & DTS surround soundtracks work fine, but any films encoded with a multi-channel AAC soundtrack play back only in stereo.

Is this a case of the Pioneer not supporting multi-channel AAC or is there another issue causing this? I can't find any information in the manual or on Pioneer's website which states specifically that the VSX-921 does or does not support multi-channel AAC, only that it supports AAC. Can anyone shed some light on this? Thanks.

Thanks for the response, JDSmoothie. I suspected something like that - it would be helpful if manufacturers were clearer about these capabilities in their manuals.