Been there. If you haven't seen this, it's somewhat useful in that scenario:
"If you find the binding rail is out of line a small amount to left or right (usually due to slight ms-alignment of toe unit screw holes), try simply holding binding rail over in correct direction while you tighten screws. If that doesn't do it, remove some of the front screws and look for which screw holes line up the best with binding when the binding rail is aligned with the heel unit. Insert those screws first. These methods are usually all you need to get perfect alignment."
http://www.wildsnow.com/articles/fri...-freeride.html