Ok, I know this thread is a little old but I wanted to post here for anyone that may have a future problem with this.
Basically you end up with a loop at the very end not because of your cast on but in the very beginning of your 1st row something becomes loose. So make sure everything in the beginning is right and you won't have this problem. I know it's hard to figure these things out just by reading about it and I didn't exactly know how to explain it.
I just got through trying to fix my row with the same problem and I think I started a new cast on 5 times.