Much like Tauwasser's gut told him, my gut told me it was a problem with the scrolls getting out of hand. I've been hacking this game for years so I know my way around. In this case it was the BG2 offset at RAM locations $7E011A and $7E011C (going off memory here). These numbers get added to the Y and X scroll values, respectively, for the screen. It causes the "quaking" look on the screen by quickly alternating between -1 and +1. I tracked down in the code of the game where $7E011C was being written to during the Ganon fight. I used a write breakpoint on 7E011C in Geiger's Snes9x Debugger. From there I determined (by going backwards) that the values for the scroll offsets were being read from CPU location $1D8000 (which translates to $E8000 in the rom). You have to know 65c816 assembly language fairly well to understand what's going on though. After I determined that those numbers were nonsense I looked at a clean rom and just copied them over to test it out. I surmise that the source of this problem was Hyrule Magic screwing up on monologue b/c you said your hack had extensive monologue changes (it's a translation after all) and by the fact that 7F is the byte that in the monologue data indicates "end of message" and that 80 indicates "go to the second set of monologue data". It's just too much of a coincidence for it to be anything else, I think.

As for the crashing itself, it seemed to be random whether it occurred at all. I didn't bother looking any further what was specifically crashing in Ganon's code due to the scrolls being off b/c I was sure this was the answer.

http://www.romhacking.net/docs/365/

Those are my documents, though they're a bit out of date, probably should update them soon. There's a ROM map in there but I'm not terribly proud of it. I've put a lot more effort into the RAM maps (RAM and (SRAM)).

I also have a full disassembly of all the code in the game which is not on romhacking.net. I've long thought about posting it but I've been hesitant over legal concerns, but last I talked to Nightcrawler he thought it would be all right as long as it didn't contain a fully compilable document that one could use to create a rom.

Finding the "copy ok" and "erase this player" text would probably be pretty easy. I'm kind of surprised it isn't in Hyrule Magic... are you positive it's not in there?

I'm guessing you changed the equipment graphics in hyrule magic using the graphics properties dialog.

I'll find those two strings for you "copy ok?" and "erase this player?" for you. Is anything else holding up the release of the translation?

I'm guessing you changed the equipment graphics in hyrule magic using the graphics properties dialog.

I'm not really sure what method you were using to change the text. Probably a table file? Anyways I'm pretty sure I've located those two strings.

"erase this player?" is at 0x06541E, length 0x64
"copy ok?" is at 0x06523A, length 0x30

(assuming no header)

Now it's not so simple to modify this data correctly.

There's actually several different sets of data in those sets.

Also, the top row of 8x8 tiles is copied first, then the bottom row of 8x8 tiles is copied. Without knowing exactly how you plan to modify this I'm not really sure what to tell you. It's editable but you need to be careful or you might crash the game (just trust me, I did it on accident while playing around with this a handful of times.) So without knowing the text you want to change it for it's kind of hard for me to tell you what to do just yet :/.