I’ve just come across this having had similar problems myself. There didn’t seem to be any rhyme or reason to why my video was failing as it was due to patterns rather than flashes in my case.
In the end I just used the guys at hardingtest.com to resolve the issue, uploaded my footage to them and they got it fixed, mastered it to digital betacam then delivered to the broadcaster.
Still racking my brains as to what went wrong though!