How to break your rom in one easy step: …I have no idea, I was just cleaning up some text files and this happened.
EDIT: (Warning: explanation babble)
Copier headers, like many other SNES issues, are to blame. 512 bytes of uselessness trip you up annoyingly often, especially when one text file requires you to turn off the header size command because the pointers used are based on the base of the pointer table instead of the base of the bank, therefore causing severe underflow and thereby pointing to something else entirely. Why did I write up a thing about me breaking my rom? Because headers are annoying, and I needed to let it out in the glitches thread in case anyone understood my babble. The end.