You must dump and inject when you are ingame, not in the title screen.
I know. I'm injecting in the game, not in the title screen.
I've done this several times before and it worked perfectly. I'm saying that after injecting, it'll appear absolutely normal and then once I save & quit to finalize the map changes... it corrupts and won't let me even get to the title screen. It forces me to delete that save or else it's useless.