It seems that it does at least some sort of partial reboot though if standby is used, as I notice that the "mute" state that a leave it in while not replaying is reset after return from standby and also I lose my HDMI connection. I have to reinstate this by crawling behind my installation and unplugging and re-plugging the HDMI cable. This is caused by a HDMI switching box I have to use on the single input to my TV. It has always done this after a reboot which is what made the previous fault condition so inconvenient for me to work around.
Still I can perhaps avoid the issue if I just avoid standby. I shall see how this works out.
Once this new f/w proves stable, here's hoping we can convince 2lostkiwis to pay another visit.
I had almost given up hope of any further action and bought a Panasonic as a replacement, though, until now it remains in its box.