709er, sometimes the start up order can affect things.
With the projector off at the wall, try starting the AVR, then the player, put in a standard blu-ray disc and whether it plays the audio track. Then turn on the projector.
If this doesn't help then I'm stumped and your options are new AVR or use one of the HDFury workarounds (they've got a new AVR Key due in October).
709, i imagine the projector is hdmi v1.4 since if doing 3D ? the sony avr though is v1.3 if remember
for 3D have you been splitting so far. ? is that why want to continue doing ? its something i did too when ran 3D with a 2008 processor
typically the splitting is only needed these days if say were running a uhd display... in which case you run video direct to the display. audio direct to AVR it can be a bit hit and miss in some cases. some of the players have a setting as to what you want to specify for each hdmi output.