I'll try to fix the bootloader.
I use the Duemilanove, upload the ISP programmer from examples. When I switch the board to 2560 (connecting the 1280) I get the following error
"avrdude: Expected signature for ATMEGA2560 is 1E 98 01
Double check chip, or use -F to override this check."
I'm sorry for this question: is there a secure and not to difficult way to get the bootloader onto the 1280?