This DVD was shot on HDV, mastered to DigiBeta then encoded on a hardware Minerva mpeg2 encoder and authored by Scenarist. The white lines are not consistent throughout the length of the film. The DVD is 2 hours of live performance and the white line only appears 3 times (3 tracks) throughout the whole piece, and is half of one horizontal line always at the top right. It is not evident on the original footage, nor the DigiBeta and only shows on the DVD when playing it through a computer or a 4:3 monitor.
I'd guess that comes somewhere in the transcoding- either at the Digibeta stage or on the minerva encoder. And you wouldn't see it on the monitor because it's out of TV safe area. The only way to fix would be reencode and crop as needed.
However I must disagree with you about the TV safe, broadcast monitors show the entire picture including the TV safe area. They also have an H/V delay function to show everything outside the visible picture.
I have now ruled out Minerva as the source of the problem because I have played the digi through the ARC replacing the top and bottom 2 lines of picture with black then into Minerva and that has solved the problem. If Minerva was putting the white lines there it would still put them there over the black.
I have checked some other video which was played out to digi and then encoded on Minerva from both before and after I did this job and it's all fine. I've had a close look at the original files and even zoomed to 800% there is nothing visibly wrong with it.
That said and done the only solution available is to crop. Not ideal and would still like to hear other input from Cow Community members to see if anyone else has had a similar problem or whether its ghosts in the machine.