Irrlicht Engine

I have a carema a CollAnimator:

scene::ICameraSceneNode* camera = smgr->addCameraSceneNodeFPS(0, 100.0f, 300.0f, -1, 0, 0, false, 0.f);

scene::ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(
metaselector, camera, core::vector3df(20,80,20),
gravity,
core::vector3df(0, 70, 0),
0.00f);

In scene I have a stairs. But when I go to it the camera begins jumps. And when I go to the obstacle of hight nearly 80 camera goes back far from this obstacle.

Sorry, for bad english. And thanks to all. Please help. What do I do wrong? May be I miss some parametr of camera ?

gravity is (0,-50,0)

And I have nearty 6-8 fps with my big scene.

If you could upload a compiled executable with all the required assets then we could try it out and see what's going on, as i don't particularly understand what you mean from what you've said.