jharris1993:
In this question, the individual had an atmega 168 chip, and had created a program that caused one of the internal fuses, (the extended fuse - 0x7), to blow, causing the chip to become inoperative unless re-flashed.He discovered that he was causing the issue by overruning the existing ram:
No, that's impossible. The only way to change a fuse is with an ISP.
You can write to the flash memory using special instructions but it's much more complicated than writing to RAM and the bootloader section is usually protected from overwriting.
What that posting refers to is the uploaded program not working once it gets too big to fit in memory. Nothing more.