UH-OH! Sounds like the same issues I had a week ago. I'd call Anthem; Nick or Pierro. They will probably tell you to deinstall then reinstall the driver for your serial to usb adapter(hopefully you have "their" recommended Key-Span adapter). Then remove the current v1.33 from your computer then re-download from their site v1.33, try to upload to your D2. If that does'nt work, they may recommend running the Flash Eraser program from their password protected tech site. I would run this program several times(5-6) then try to reload the current v1.33. This should work, if not, you'll probably have to return your unit to Anthem. The above worked for me and I hope it'll work for you as well. The guys at Anthem know what they are doing and they will do their best to help you in your time of need. Good-Luck and let us know how it turns out.
P.S. Also, make sure any powered HDMI sources/cables are disconnected, not just turned off.