I've never used one, but I believe this is expected behaviour. It's within the overscan area of the frame, so the designers of the device wouldn't care about that portion given that it was created during the era of CRTs.
See the paragraph underneath the first frame grab:
http://www.digitalfaq.com/forum/vide...converted.html
There is likely an internal adjustment to alter the "window" that is processed, if you are technically inclined.
EDIT: Linked in one of the Similar Threads at the bottom of this page...
http://www.digitalfaq.com/forum/vcr-...-bvp-bvp4.html