I'm afraid this is gonna be a problem that everyone is eventually gonna face...I had the same thing happen and when I asked my buddy that runs a body shop he said the problem is "there is no hardener in this enamel paint"...
Think about it...you're buffing paint that seems dry and hard but really in a microscopic level it is still a bit soft and when you buff it, you are scratching it. It's a no win situation...no final sand/buff leaves peel and trash, final sand/buff leaves micro-scratches galore...
I'm still scratching my head trying to figure out how to salvage my paint job since I completed the whole car before I figured out this problem!!