I'm new to microcontrollers / Arduino and cannot seem to figure out what I'm doing wrong. I have an SMD Uno with serial #317856 and I think I have the bootloader problem because when I plug in the board, the last sketch loaded does not run. It's supposed to, right?
I've followed the procedure documented at http://arduino.cc/en/Hacking/DFUProgramming8U2
5 or 6 times. I'm using Windows XP SP3 with Flip v3.4.2 and after a reset the board shows up as an AT90USB82. What is a puzzle is that when Flip updates the Atmega8U2 with Arduino-usbserial-uno.hex it does all the steps (Erase, Blank Check, Program, Verify) in < 2 seconds which seems too fast? When I tried updating with Arduino-usbserial-mega.hex it spends about 20sec on the "Program" phase then fails with "Cannot write to USB." Back with Arduino-usbserial-uno.hex -- everything works according to the procedure but after unplugging the board and plugging back in and then loading a simple sketch ("Blink"), that runs fine but after I unplug and plug back in the sketch isn't running. So I'm lead to believe that the firmware is not fixed.
Maybe I have the wrong firmware .hex file? The md5sum I have is:
Maybe I have a different problem?
Thanks for any advice you can offer. I'm stuck.