How to keep rigid body objects from going through a plane

I have a ragdoll that works in the game engine. My problem is when the ragdoll is dropped high up, it gains speed do to the gravitational system which causes the ragdoll to go through the plain instead of bouncing off. Does anyone know how to fix this issue? And my bad about spelling plain wrong in the title…

In the World / Physics panel try increasing the Physics Steps

Is this a ragdoll for 2.5, if so would you mind sharing?

It works in both 2.49 and 2.5. But it isn’t skinned.

How do I give the plaine a thickness?

Edit object => extrude (E), maybe also check collision bounds, basically make it a thin cube