Never dug into it myself, just going on what
@M Code , an industry guy has reported on the subject, here's a quote from a thread earlier this year:
"This needs clarification..
The primary reason Marantz and Denon products have issues with HDMI/HDCP compatibility is that their products are
not certified. Instead they do their own self-certification in-house which falls short, especially for interoperation compatibility with other brands/modesl HDMI products. The only primary brand that has HDMI/HDCP certified AVRs is Yamaha, note that the cost of HDMI/HDCP is expensive ($35K/platform) and delays 1st shipments by 4-5 weeks."