PhysX objects & TGEA triggers problem

Hello !

We are students in the game industry. Currently doing our game project to validate our year, we've encounter some problems.

We succeeded integrated PhysX to TGEA 1.8 (from the following ressource : http://tdn.garagegames.com/wiki/PhysX_in_TGEA_1.7), we've got a correct rolling ball as we wanted.
Now, the problem we got is that we can't use triggers with our rolling ball.
The PhysX object we use (a ball) does not react with actual triggers and we don't know where to start to solve this problem.
The PhysX actor created via the PhysX overlay isn't really like the
basic object (rigid shape) given in TGEA.

Thanks for yours answers !