Hi SW,
When did you start getting the lines?
If from the start then.....hmmmm....
If from an update of your drivers then I would suggest (unless you need newer drivers for another game etc etc ) clearing out the driver and installing an old one (say one that came with the card).
CFS2 does not need very much in the way of graphics or CPU power.
Have you recently installed a video viewing programme or udated/upgraded one?
Give the driver down grade a go, an let us know.
Cheers
Shessi