Not sure why you want to fix this. Non-zero ILVU End values are OK in a multi-angle DVD. I don't know why some parts of the movie are lost when you remove the angles. Perhaps a new form of protection ? Anyway, if the DVD works correctly, I suggest to leave it as it is. Otherwise, have you tried
FixVTS ? Usually, it gives good results, but it works in place, so be sure to apply it on a backup.