You can try fix this yourself
(which actually fun)
Or just use my fixed here
BTW : I won't pull request back yet because it too much hack and slash there, I'll wait for stable release to avoiding refracting conflict ;)
PS : Long time no code in AS3 woooot!
just like i said it's kinda hack for learning and after asking for more detail on this via google group, turn out that that all physic stuff is get heavy refactoring there, nore detail via devcast here https://www.youtube.com/watch?v=XvH6g6h6JRQ i will revisit this again...not so soon ;)