Also I've checked and it is indeed different in v2 versus v3 because of the changes made to intersection tolerances. Those changes were made about a year and a half ago.

The changes were a result of this example model posted here: http://moi3d.com/forum/index.php?webtag=MOI&msg=5266.1 if you try sweeping that file, you'll see that v2 makes the weird result in that case, and v3 does it better.

Unfortunately the same change that made that file behave better made your particular case here behave worse...

- Michael