Odd situation that may not be a bug in survival mode.

Sheering a sheep prior to 0.4.0 led to a couple of minutes wait before a sheep could be sheered for wool again.

I've just been in a situation were after sheering a sheep the wool regrew within seconds allowing me to farm the animal three consecutive times. There was another sheep in the area which also reacted the same way supplying 5 pieces of wool in total before then staying the sheered state.