I noticed something interesting when learning a layout I designed. (I am not using it right now, still learning it.) The typing program I uses teaches 2 keys at a time. I noticed that I never mixed up 2 keys unless I had already been practicing those positions. For instance, my layout puts B in the Colemak G position, and Z in the Colemak B position. While I still hadn't practiced the bottom row, I never accidentally put B in its Colemak position, but as soon as I began practicing typing Z, I accidentally put B in its Colemak position a bunch of times. Any thoughts on this?
My typing speed record: http://hi-games.net/typing-test/watch?u=493