Scene is for static geometry, prop is for dynamic stuff (pushable boxes etc). Have you generated a physics model for your objects? Assuming you haven't already, do the following:
1. R-click on the mesh in the assets tab, selecting "generate shape" and picking one of the two options. Since these seem to be static meshes that you're going to be walking around, I'd suggest you pick "polymesh". It'll prompt you to save the resulting PHY file. Give it a name and save it to an appropriate folder.
2. Place the mesh in the scene, click on the "Scene" tab on the right and select the physics tab at the bottom to edit the physics settings. Change the "Shape file" to the PHY file you generated. Set collision type to scene.
3. Save the map and test.
Hopefully that works, because otherwise I'm fresh out of ideas.