Mega and no ttyACM0

Hello, i want to work with an Arduino Mega (Ubuntu Meercat). It doesn't work (like discribed). So i updated like this: http://www.pluggy.me.uk/arduino-ubuntu/ I followed exactly all steps, but there was a communication error (?). Than i followed exactly: http://arduino.cc/en/Hacking/DFUProgramming8U2 After: Reset the 8u2 the serial port is no more available (ok). After: Program the chip sudo dfu-programmer at90usb82 erase (that works) sudo dfu-programmer at90usb82 flash Arduino-usbserial-mega.hex (doesn't work!!!) Error parsing the line. Something went wrong with creating the memory image.

What does it mean? What can i do?

Did you ever figure this out? My ubuntu also won't show ttyACM0. I have to boot to windows just to update my f/w :(

My Ubuntu version (11.10) is ok now. There was a permission problem, but that was easily solved. Without having to repeat myself, here is the other topic with the fix (for me anyway). http://arduino.cc/forum/index.php/topic,81736.0.html