so, nothing about this is going to be easy, huh?

when i drop the wonky track into the project and line it up and export it, it nulls with the old file (while not nulling within the project, which seems crazy to me). then when i save it and re-open it it goes back to the new file. further, the identical files that don't null on the direct insert now null after the save and re-open. this is repeatably demonstrable, if still completely incomprehensible.

in order to be sure that what i'm comparing is stable, i have to be able to create a project that will null with the old files repeatedly and predictably. given that everything is resetting on the save, and i think that this is related to the project file, i think the only way around this is to render each track separately and build a new project. then, i'll know for sure that the out on the wonky track is really the out on the old files, and know which one i should be using.

preliminary testing suggests that a new flat render on the wonky track does null with the original file, indicating the error is on the insert. but in order to be sure that i've actually found the problem, i just need to be sure that the old flat render doesn't. if i can't get there - if it nulls through both renders - then i can't be sure i've actually solved anything.

and, if i'm not able to determine that my signal is flat, i'll have to wipe out the project files and start over.