Sort of a late reply on this post, but I had the EXACT same issue, and our resident troubleshooter had an idea that worked. All he did was export the troublesome clip from the P2 Content Management Software (came with the camera…or you can download it) and even tho’ it simply exported, or I guess transferred/copied would be more accurate, a CONTENTS folder (with all the standard P2 specific directory structure), it seemed to have corrected what was wrong with the offending file. Weird. But it worked and it took very little effort.