Im in the same boat, failed with generic usb-midi so after much hair pulling purchased m-audio midisport uno (as recommended). No difference here. Support ticket was replied to saying try with midi connections in other sockets etc and alternate usb sockets, done that no change. One thing I noticed though was that when the amp was powered off and I plugged the "to midi in" on the uno, to the midi out on the DT25 (as suggested by support) the DT25 main red led illuminates. This does not light up with any other cable in any socket. I would like to know if the led should be lit with the amp power off and what power state the amp should be in when attempting the firmware update, i.e. off, standby, fully on? Anyone got any ideas? Will ask on my support ticket see what the reply is.