Does this still happen after a total power down and re-start?
Have you tried changing the resolution in the OS, then start catalyst?
Does a resolution / refresh rate change make a difference?

There are so many LED screens that start at 0 pixel - and don't have any way of offsetting the start pixel...

One workaround would be to use a scan converter on the DVI output and shift the image back by 1 pixel.

S