Not familiar with B3D Mesh IrrlichtWrapper in Freebasic, and this is not a solution, more of a check list.
One thing you might want to try is, in making sure your camera positionings are correct. I often get confused with the z position, maybe you are too. Also check that the position of your mesh is correct.
And one other after thought, check where your media is located. Perhaps you have other folders they are in?