Cat drowned in boat (Pre-release 5!)

I understand this was "fixed" in the 5th pre-release, but my cat still drowned in a boat. I've tried to duplicate it, but it hasn't worked. I was using a boat with my cat in it, and it started drowning.

 

Update: I put the cat into the boat, in pre-release 5. At first the cat didn't drown, then I took the cat out and did some stuff, and then I put it back into the boat and it drowned. I put the cat in the boat the first time not sitting, whereas the second time I put it in sitting. I tried this but it doesn't make a difference.