Sorry, but my earlier post about mode 2 not initializing the network properly was the result of a mis-observation.
Here's what I see for all the modes..
Modes 1 and 3: Monitor on .... OK
Modes 1 and 3: Monitor off ... seg fault during boot, no network
Mode 2: Monitor on or off ... boot completes and network comes up and (if monitor is turned on) menu displays
The receiver reports that its HDMI input port is in "DVI" mode, which seems understandable given the purpose of Mode 2.
(conversely, in Modes 1 and 3, the receiver reports that its HDMI input port is in "HDMI" mode)
So, in Mode 2 the Id is up and alive, responds to menu requests, and network pings, there's just no audio coming from the receiver.
If there's some diagnostics that I can collect, then do let me know.
Dave
P.S.
the seg fault during boot for the no-monitor Mode 1 and 3 case seems odd because there is indeed an HDMI device attached (the receiver).