I just tried that again, and got an instant FCP crash (“unexpectedly quit”) as soon as I tried to play the imported clip. Luckily it didn’t corrupt my project again (although I did use a copy this time — once burned, twice shy). I think it really doesn’t like the mis-matched size, pixel aspect ratio, etc. Plus I imagine FCP would not want to play well with the Media100 quicktime component. That’s why I’m trying to save it as a more normal QT file first. Thanks anyway — I’ll try this question in some more Media100-ish forums.