Hi there is a firmware upgrade. Thanks Mikesthlm

First one in a long time.

i can confirm it didn't fix the Audio Input Signal displays incorrect format 3/3/.1 problem on my model.

The Japanese web site says:

AV Surround Amplifier AVC-A1HD
"(1) Improved the behavior of certain Blu-ray Disc."

The 4310 got a few more fixes

(1) The specific behavior during playback BD software was improved.
(2) HDMI connection for improved operation.
(3) Improved connection behavior and internet radio show.
(4) various other operating improvements.

All vague........

Cheers

Dominic