Like, one extra loop total, or an extra loop for every stitch? If the latter, you may not be pulling the index finger yarn THROUGH the thumb loop. Are you accidently catching the thumb loop in the process with the needle? You should be going through the loop completely, and not catching it with the needle, so that the thumb loop yarn closes around the other yarn, but not around the needle. If that makes any sense....
KnittingHelp Queen Bee
It is not because things are so difficult that we do not dare; it is because we do not dare that they are difficult.