That explanation doesn't make sense to me. I can scrub or play in the iMovie app just fine. Somehow iMovie will skip, blank, or otherwise deal with the single corrupted input frame (and in fact, I don't see anything wrong with any frame when I'm just going from frame to frame in the app itself), and play the entire edited movie for me with no trouble. It is therefore possible. But when I export to a file, the entire export stops upon encountering one corrupted frame in the input. Not even a dialog box that says "corrupt frame encountered, skip Y/N". So I have to try to find that one frame given an absolute frame number (hey, guess what, the iMovie interface only tells me seconds, not frame numbers, so more fiddling), finally excise the region I think has the bad frame, start another 10 minute export, until it finds the next bad frame (turns out there were 4, widely scattered in my hour-long set of clips). If a single bad frame can derail the whole process, then that's all the more reason for the software's logic to account for this possibility and give the user at least an option of automatically excising the minimum amount that will let it continue starting at the next uncorrupted frame.