SamyGO

I am also getting the "no software to upgrade currently" error. I assumed this was because the firmware was "unsupported" - thus why I volunteered to be a guinea pig. I followed the steps davidx posted and got this exact error every time.

I have a US (Region 1) BD-D5700ZA running 1028 firmware (6/21/2012). I would like to guinea pig for the downgrade.