Problem with distortion at edge of monitor using Dual head2go

Hey guys, I getting an intermittent but fairly regular problem with the display of my monitors, using my dual head2go. I am running 2 24inch Samsungs, at 3840 x 1200. What happens is that at the right hand side of each monitor, the last half inch vertical slice of screen distorts, as if it is wrapping round something into the monitor. Does anyone have any ideas what may cause this? As I say, its not apparent all the time and its also showing on the desktop as well, so not FSX specific. I have tried the obvious, updating the Matrox software etc.cheers, Mark