Ok this one is going to sound silly. I have read and looked at the pictures showing how to align the cartridge and atty. I find it difficult to do it correctly unless I have a very bright light to see inside the atty. It is quite difficult when in a darker area and even worse when I have the cone on to see down the tunnel. It would be great if carts were made so they only fit in one way or if there was a little mark in the atty ( kind of a this way up) that we could see more easily. I am thinking of using a drop of nail polish on my attys to mark the direction so I know which way to put the cart in. Anyone else have this problem and solutions?