You know how the BoF2 "improvement" patch expands the battle background so that it fills up the entire screen?

...I'm trying to kill that glitch.

Yes, it's a glitch. Take a good look at the patch of background behind the fancy translucent battle status box. It's just the top edge of the battle background sneakily looped around. Not only did d4s cheat on this count, but once you notice the trick, it actually looks pretty damn bad. (Check out the fight with Katt/Rinpoo/Lin for one particularly egregious example. Whoops.)

Now, here's the part I'm beating my head against. Not only does the background not visibly loop like this in the original, but in Mt. Futabi (and I suspect other areas as well) he's got it working like the original, i.e. no loop-around. Checking the save state in VSNES only adds to my bafflement: the preview and BG1 viewer both show the background looping vertically in all cases, including the original; my guess is that there's something that prevents the looped background from being displayed, but damned if I can figure out what it is, let alone how d4s selectively broke it.

Any SNES geniuses have any idea what the hell is going on?

EDIT: Stupid me. Finally figured out what I was looking at: I still don't know what an "IRQ cutoff" is (my only experience with IRQs, "Interrupt Requests", is in configuring hardware for old MS-DOS games), but by commenting out a swath of code...bye-bye, sucky effect. :3