Thanks for the response…
I sent it as an audio project and it did open up again in STP. I think the issue may have been me doing a Save As initially and telling the software where I wanted the file (ah, just trying to stay organized) rather than just letting it drop the file where it wanted to. That said, when I tried to re-link the media, I go find it, hit connect, and nothing would happen. The connect media window would be empty, but the media wasn’t connected and the only option was to hit cancel…which got me right back where I started.
Sorry for the novel, but you’ll laugh at my work around. I exported the original QT file as an aiff, dropped that into STP, did the noise reduction, exported the aiff, and then just dropped that into my timeline under the original audio for the file. It worked, but it’d be a pain if I had to do it with multiple clips.