I'm using the unfinished physix 3 plugin someone on the forum made a while ago. It has some problems aswell (including bugs with joints, iirc) but for me it works. You could also wrap physx3 or another physics engine yourself.
You are probably using plugin which was made by 3dgs_snake. The first version of it, as he wanted to recreate the plugin from scratch, with the knowledge he have gained and he even started working on it. Unfortunately I don't have any of his plugins on my current PC. And yes, build-it physX won't work, cause it has already some limitations and bugs, I would love to use solid working physX 3.x plugin, but there are none and I'm not good in creating anything like that myself...
Greets.
