Your frame could be out of level and you may have also messed up the spacing between the front and rear rails when attempting to level the machine. Take a rigid tape measure (like carpenter's use) and measure the distance between your rails every inch or less. Every measurement should be the same in every place. If it is incorrect you will need help to make your frame level as it is darn near impossible for one person to do it, especially when the machine head is on the frame. You will need to contact gammel to see if they make any kind of spacing bars to install on your frame to make the distance between front rail and rear rail uniform through the whole rack. The problem you are describing is definitely rack related, not machine head related. If you bought from a local dealer, now would be the time to contact them and maybe they can have someone come out fix your rack.