Hi 'Oldie',
Same problem using (e.g.) WMP?
Version of BS.Player?
Your P.C. runs which O.S. (XP, Vista, Win7)?
Type of graphics card?
Can you let us know which codecs/filters are used by BS.Player when playing such DVD?
(to find out: rightclick > Options > Filters > Advanced further info is revealed by clicking on the [+]-signs)
(May also be a video-card or monitor defect if it doesn't only concern movies in BS.Player)