i think that the reason absolute poker changed their rake terms is due to the fact that there are now more poker rooms(skins) sharing the network with AP. as such, in order to calculate how much rake is contributed by every player based on the poker room he is playing in, they’ve changed the terms…
meaning that the player’s contribution to the rake is proportional to his contribution to the pot at any given game. this way all poker rooms/affiliates are paid according to how their players play and how much they chip in for any given pot.