Hi Ted, bear with me on this (I'm a little tired at the moment). A few months ago I had to replace the sprocket on my Craftsman opener, not a big job but I to had problems once I put everything back up. As I recall (remember I'm tired), I had to jack around with the positioning of the chain itself. I know that this makes no sense, but that was the key to the whole thing. You stated that "this is your second door", so what I would suggest is to take a look at the "first" door and it's chain's positioning. Adjust door #2 to look exactly like door #1, and then play with the screw settings.
Hope this helps, and maybe someone else can offer more insight! Good luck! Wick