I've been using Colemak for a couple years now - but instead of learning it with my laptop's keyboard, I learnt it with a new Kinesis Advantage Pro. I now find that if I'm using a standard keyboard, I can type qwerty without much more difficulty before, but if I'm using the Kinesis, I have no trouble touch typing Colemak. My guess is that the massive difference in the actual keyboards stops my brain from getting confused.