Can someone advise me about the lock in relation to the point where the knees come together for the lock movement. In New Vogue the trailing leg sits behind the forward leg for the lock and yet (after viewing another dancer) I suspect that in the Samba lock the trailing knee may come forward to the point where the trailing knee is beside the forward knee for the actual lock movement. Currently I am locking the trailing knee in behind the foremost knee. Am I right or maybe I noticed someone doing this movement incorrectly???

Are your feet turned out, back and front. Does the knee of the moving foot actually strike the back of the stationary knee with a feeling of pushing it forwards .Is your weight balancing you between your legs 50- 50.
at that point, with both heels off the floor. If this was a Cha your front leg will go to a straight knee on the forward step. If its Samba it will be straight and than bent.Then in comes the body tick, which is not there in the Cha. Get a thorough understanding of the foot position with the turn out of the feet back and front in a Latin Cross ( Lock Step) Now forget the name Lock Step. Don't compair New Vogue with Latin. New Vogue is based on Modern where the feet are always pointing in the same direction. In Latin there should be a turn out of both feet on all steps. Hence the term Latin Feet. Now if you are like me you will be trying to get the correct action in the Samba for the next 20 years.