Good... it shouldn't be. <img src="/forums/images/graemlins/smile.gif" alt="" />

Look at the Hi/Lo engaging "ring". There will be some surface before the 'valley' the shift-yolk sits in and some surface after the valley as well. One of those surfaces should have another, smaller valley (or groove) machined around it... and that surface should be toward the back of the case. I don't know if having it the other way (small groove toward the front of the case) changes the throw of the ring or not; but its worth looking at to make sure its on the right way. If it does change the path the ring travels and someone had it off and put it on backwards, that could be the issue.

You already said the roll pins are not broken. If the case has never been apart, its hard to imagine anything else that would change the path that ring travels. Do you know the guy you bought it from well enough to trust that he would tell you the truth about the case being tinkered with?