I`ve tried to upgrade the DT25 HD firmware 2.0 through my M-Box 3 (Firewire) MIDI interface. Line 6 Monkey recognized the hardware and linked my DT25. The install progressed to a particular point and then failed during the last stage of the install (800000a error probably with connection). I tried a couple of times and changed my MIDI cables –it still failed at the same point each time. After reading a couple of Forum comments, I decided to try a different interface. Fortunately I have access to a Roland Fantom X7 keyboard which is connected to the computer via USB cable. This worked without any problems which suggest that the problem may be with the Firewire connection.
Hope this helps other users who may be experiencing similar problems.