I went to the jungle on the server I play on, and came back with 3 ocelots. I started breeding them (now have 27).

While breeding, I have all the cats sitting, and only un-sit one at a time to breed with a sitting cat. The cats I un-sit, as well as the resulting kittens will not sit when clicked. It does not happen every time. I can get these cats to sit if I punch them, and then feed them a fish (they will sit when fed the fish), and they are then fine if I try to un-sit and re-sit them. The cats which refuse to sit sometimes teleport, and sometimes don't. I had like 5 of them with the not sitting problem, and ran away, but only one teleported to me.

I tried logging out and exiting Minecraft before re-joining the server, but this didn't stop the bugs.