Also after talking about the issues with the player he has asked me to send mine back as we walked through the back selection process and his 120 did it fine and mine did not so perhaps a batch of them have this issue.
He is sending me a pre paid UPS label to send my player back so they can investigate if it is a problem with the player or simply a firmware thing and if its the latter then they can go about fixing that for all of us.
I did say that a few of us are experiencing this same issue. I got my player in August last year so I don't know if others with the same issue got theirs around the same time if so, perhaps it is indeed a batch issue.
Have you tried re-installing FW 1.32 to check the "no back selection" issue vs. FW 1.37?? I have and it's definately connected to the FW 1.37, not the hardware, at least that's what I noticed.
Hopefully, you won't be wasting your time sending your 120 back when it's just a FW issue! BTW, I emailed AK about this quite a while ago with the usual "we will look into that" response...then crickets....