Physics in 1.3.1

Hey all,
I've been having trouble getting collisions to work properly in 1.3.1. I am using this physics setting:

sio2->_SIO2physic->_btSoftRigidDynamicsWorld->stepSimulation( 1.0f / sio2->_SIO2window->fps, 0 );

and this for movement:

btMatrix3x3 mat3;
mat3.setFromOpenGLSubMatrix( (btScalar *)object->mat );
object->_btRigidBody->getWorldTransform().setBasis( mat3 );

When I make my player object dynamic it just sits there and is unaffected by physics. When I make it a rigidbody it falls through my ground mesh in jerky steps. Until now I have been doing that as a workaround: exporting most of my scene with 1.3.1 and running it in 1.3.1, but using the 1.2.1 exporter to export the player object. What do I need to change to make the player function in 1.3.1?

Thank you!!!