Just two notes for people updating their firmware:
a) during the update the player shows "copy firmware", don't get confused, it means "player is copying firmare". (took me two resets until I got it)
b) my player was delivered with a firmware patch in the root directory that wasn't applied until I copyed the 1.35 patch with a different name into the root. After that I renamed the 1.35 patch back to YP_M1.rom and it applied too. I don't know whether you have to copy a firmware patch or just any file to the player to make it recognise the first patch, just try if you have the same issue.