Minor video problem - In fast scenes the screen splits in 2

[VitalyB]

When there is a quick motion in the screen I can see in some movies the screen as split in two - The upper 50% of the screen is lagging behind the bottom 50% for less then a second.
The problem is, as I said, minor, but I would be glad if someone points me to the problem.

[Tecno2k2]

Enable vsync :)

[VitalyB]

Where is it in BSplayer options?

Video->Wait for vertical blank?