I have a pocket door with an open track. One of the wheels broke off, so I replaced the wheel. I thought that was too easy! Now when I close the door, everything is fine until the door has about 4 inches of opening left. It won't re-open unless I actually lift up the end and then it will roll back fine. Both wheel are still on the track, but the back wheel doesn't want to move. There's an adjustment screw on each wheel assembly - I adjusted it to so that both wheels seem to be at the same position. Any ideas??