I totally forgot about Teioh ! Thanks for reminding me, I'm gonna try it ASAP.
EDIT:
Wow, now this is amusing. Upon loading it, Teioh says that it is not a Kernel2.bin file. I click OK on this message window, and still notice that the program loaded my text (in the command tab, I read my "you need the item materia to use items" stuff, etc). But the program crashed, as the mouse cursor is eternally blocked into its hourglass form (until I close Teioh, of course).
Apparently, the file got corrupted (after my many changes, I guess) somehow. The weird thing is, the game itself doesn't seem to mind about this corruption. Only utilities see it with a bad eye.