You can have three docks, each with 5 places, and you can scroll through the docks. I presume on the post that was originally referred to that the poster had simply scrolled to a different dock after he had changed home screens. Not that the dock actually changed as the home screen changed.
THXS for the clarification!

I also am challenging myself to limit myself to only 3 home screens. I normally always use 7 and mostly use widgets, but I cleaned up everything and as you can see really cleaned my home screen, normally it would be completely filled. Launcherpro with 3 docks helped me place apps there instead of on home screens.







