Yamaha DV-C6770 5-Disc Progressive-Scan DVD-Audio/SA-CD Changer
Obsolete firmware do not buy
I had the same issue of the unit freezing when trying to play the new talking Heads DVD-audio discs.  Yamaha will send you a refurbished unit if you pay to ship yours out to them, but they admit that won't solve the problem which appears to be firmware related.  Yamaha offered no other solutions.  Further online research showed people having the same lockup issue with Neil Young DVD's from 2004.  Shame on Yamaha for not making good on this