The reason I asked about the software is because most hard disk recorders and memory recorders use the FAT32 file system which limits your filesize to 4GB and causes a single recording to be broken up into several files. The software stitches these back together into one large file so that what you recorded is what you get. I was thinking that maybe this stitching would causes a re-write and thus fix any problem with the file. You might want to search the Sony site and see if there is any software you can download for your camera. Just something to try.
Of course, this may also be why the camera was being sold used on eBay. Maybe it has issues? With tape, we always record black leader and color bars at the beginning. Perhaps you should create a short black clip as the first recording so that you don’t care if the first file is always bad because it won’t be anything important. The fact that it’s always the first clip leads be to believe it might be a camera issue with writing the first clip. Still very strange. You should not be having this problem.
If you can upload a small bad clip somewhere we can download it and test it on our systems for you.
~jr
http://www.johnrofrano.com
http://www.vasst.com