I've been reading this thread and I can feel your frustration. I'll never understand how cats that used to get along very well will all of a sudden hate each other and just want to fight all of the time. Pearl and Storm used to be inseperable and they always cuddled together. Now they fight with each other most of the time. They can be in the same room together and once in a while I will catch them cuddling but their relationship isn't what it used to be. I've also heard that this can also happen to littermates. My females are also much more territorial than my males and they don't seem to accept new cats as easily either. I hope that your cats will start getting along better very soon.