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#21
What does your amp manual say about setting the input type? Is it automatic or do you have to select the type of compression? Your amp specs listed a lot of compatibilities but I couldn't find a manual. Also, I'm not sure Catalyst provides Dolby compression. I would think that's provided by your graphics card.
I would take the amp out of the equation until you get your HDMI working. Plug it directly into the TV input and select that plug as your TV input. (If you haven't already.)
Also, clicking on the Advanced tab in Properties window should allow you to select the compression.