To help you guys out, I deleted a large chunk of the single player file to test a theory, and sure enough, the game loaded and letting it sit there for an hour and a half on my DS (R4) it didn't do the screen thing. Whatever I cut A) was part of what was causing the problems, B) was at the last 1/4th of the file I cut C) screwed the opening level up to the point where all collisions were screwed.
This also disproves the CRC check everyone was babbleing about, because clearly the game doesn't do one. If the game crashes on you when you edit a file, it's because you are using what is known as NDSTool, which utterly blows for reconstructing a NDS file and keeping pointers in their proper positions for games that require it (Such as New Super Mario Bros and now, this). If you want to poke around and use your edits, get NitroExplorer, located here;
http://jul.rustedlogic.net/thread.php?id=1968