And it looks like this is still an issue in PES 6 as well.deluxxe said:vertical sync helps a bit, but it's still there. Unfortunately i don't think the game is optimized for LCD monitors. They kind of have a different aspect ratio which causes the screen to stretch a bit vertically. my guess is that their is not enough info on the screen to fill it up, so it breaks a bit around the middle of the screen.
Sadly, this is still an issue in PES5