There’s also a quality issue…many classic DW eps I rip have a ghosting effect.
This is why you need to make sure you’re working from a PAL source instead of the awkwardly standards-converted NTSC versions.
Of course, there’s still ghosting in some of those thanks to restoring from film conversions instead of original tapes, but your brief description sounds like PAL-to-NTSC interlacing issues to me.