I think I do the thing Greg described. I often find myself having to step forward when recovering snatches as my weight is on my toes almost. However, I do consistently land further back from where I took off. When I checked out some video footage, I do seem to flex the knees and sweep the feet back, so that although my centre of balance is in the same place, my feet are behind it so I end up having to stagger forward or just missing it.
What's the best way to fix this? I do footwork drills often. Also what has seemed to help is making a concious effort to not jump off the ground. My feet will leave the floor, but return quickly and usually in a better position. Is this advisable?