FVA, the new trigger came out this year. There was an X-Mark that came out in 2007 and ran throught 2008 but it was not "externally" adjustable. You can adjust the new (2009) X-Mark pro just like you would adjust the 2007-2008 version. Here's what I did;

I found a picture of the x-mark (non-externally adjustable) trigger, and the method for adjusting it. http://www.benchrest.com/forums/attachment.php?attachmentid=6024&d=1215829762

What I did was to set the external adjustment so that it was at 3.5 pounds (the factory setting), then adjusted the adjustment screw (the one with the red arrow pointing to it in the picture. leftie loosie, rightie tightie. Mine is now set at a nice reliable 40 oz. pull, with no slam fires. If you adjust yours, make sure it doesn't release when you slam the butt on the floor.