Monitor issues tearingFollow

quad 9550 8 gigs of ram
ati 4870 x2 2 gigs of ram
windows vista ultimate
lastest ati drivers
running 2 samsung 24" 245BW LCD's

the issue is when showing video files or games
xvid, divx, and even some games.
seems to be a line or tear running through the middle of the screen horizontally.
the tear goes from a line to almost a inch wide at times happens on either screen.
only happens on moving images the faster the image the worse it gets.
any help to get rid of this would be great.