Just a quick addition: I've been finding the same problem with my S3 for some time, but I didn't find the time to investigate - thought it was my wireless remote playing up. I've just tried it with the simple wired battery and switch remote.
With Enable Remote on, the display shows <USB> all the time, whether the remote is plugged in or not and whatever settings I select for switch type and control mode.
With Enable Remote off, the USB remote acts as you might expect when connecting to a computer: off = record mode; on switches to playback mode.
Has something been changed a few months back?