Some cats just don't use the classic tail signs. My Rochelle flicks the tip of her tail...and thats it. Really. Very rarely she'll hold it straight up when she's really excited, but other than that...flicking the tail tip. When we first brought her home, I thought she was either really uncomfortable, scared, or annoyed, but in the 6 months we've owned her she's still done nothing but the tip of the tail flick. And I know that when she's getting petted in the spots she loves, or is being groomed with her favorite brush, or when she's kneading and purring, that she's not annoyed or scared, even when she's flicking the tip of her tail. She's just doesn't use her tail expressively.