I'm bootloading an Atmega2560 via an arduino uno using Nick Gammon's bootloader. Once I bootload, I can upload a sketch onto Atmega2560 by removing the 328 chip. However, if I try to upload another sketch, it doesn't do so. I have tried it on other Atmega2560 chips as well. The solution is to bootload the chip everytime I want to upload a sketch to the 2560. Is there an easier way to do it? Or a way to permanently fix this issue?