moving in terrain


In design mode how do I stop camera from moving through terrain.
I have a FPS that now moves into the ground instead of moving over the small hills.

For some reason it started off OK but I must have clicked something as now I move into the ground, but before I moved over the ground?

It is the 3D buzz tutorials. The camera doesnt move on the ground properly.
How do I tweak it so it does?

in 3d buzz there is further tutorial to deal with gravity. so once you reached up hills you will again get down with gravity using raycasting.

OK I fixed it.

The character controller had transforms not set at 0,0,0 and this seemed to mess things up visually with the camera. I dont know why but it is beginners error.
I walk through terrain like this?