aTV Flash and Remote HD-No Volume Control

I have just bought and installed the aTV Flash for my Apple TV 1st generation, atttracted by all the " sales pitch" at firecore.com which says that when combined with Remote HD, it will bring AirPlay to the 1st gen. Apple TV.

Unfortunately, when playing music on my Apple TV or any video source, in either case controlled by Remote HD, I either get no sound at all ( when in video, TV, movies etc ) or sound jumps around and jams ( music ) and cannot control it with Remote HD. Anyone else have this problem and/or know how to fix it?

 

Thanks