Falling through the floor

I have a test game that consists of a plane a two unit cube in the center of the plane,
and a camera parented to a second cube which is the player.

as soon as i make the cube actor->dynamic and start the game the cube which starts a bit above the plane falls through the plane. the plane has a material.

i have another game that i wrote that started the same way, but i poked at it for awhile and went on when it started to work. Comparing the two i cant see what is different, but that is probably because i am not looking in the righr place.

what does setting the cube to actor change that the player falls through the floor. It is interesting the first time but gets booring by the second.

Make sure the cube doesn’t have ghost mode enabled.

Ghost is not selected and Bounds is set to Box

Make sure the cubes are aligned with their pink dot properly. If the dot isn’t in the centre of the cubes, it’ll fall funny. To align the object to its dot, move it around in edit mode. Also do this with the plane. Next you can check to see if ghost is enabled on your plane. Otherwise, you could post a .blend so we might better diagnose your problem. The third option is probably best.

from what ive read so far, the best thing to do would probably be to post the .blend so we can help.

Boy am i blushing. i just selected the plane to see if it had anything odd set. When it turned pink i could see that the cube wasn’t falling through it, it was not over the plane to start with.
the way i was viewing it from the side it didn’t show up.

thanks tor the suggestions feels good to have help avaliable