All the code is ported, and I just went over the 1.2.1 source with a file compare tool, and made all the changes from 1.1.0 (I didn't realize you had made 2 releases in the time it took me to port 1.1.0 :P), so all the features are there (including the updated circle collisions now), they just need to be tested.
I eventually found that bug, it was a scope problem in flash where a variable declared inside a loop was replacing a variable outside the loop with the same name.
Glad that one's over. :P
You are right, probably a _lot_ more going on in one place than I will need in a game. I'm planning to go through all the vector math anyway and try to fix that up a bit. Currently each operator is replaced with a function that returns a reference to a new b2Vec2, which is horribly inefficient, but that was the easiest way to get it up and running without operator overloading. Some code will get a bit messy, but I think it will be worth it.
Motor Physics looks very impressive, definitely looking forward to it's release.
Thanks for the tips.
The last bug I had was an object being set as a reference, rather than replacing the object itself, like you mentioned, that was incredibly painful to find :P.
I'll try to release the source as soon as I have tested all of the features, and fixed any more bugs I come across.
Best of luck with your Java port. (:
I've just come across another bug, something to do with objects leaving the world, I'll have to look in to that tomorrow and upload the .swf then.
For now though, here's an updated screenshot.