If wall stuff are dropping to the bottom, this is part of what is being called the sweet down low project. These are meshes that have been altered in a 3d program to always be floor level, so when you shift the items they do not go dark and shadowy.
There are cep extra's being made that also do this. I know shasta has done a fair amount, and hers typically have two versions. The one labeled AL would have the mesh sitting at the floor.
These should be able to shift up, using the ] key. You can shift things in your game right? If not, then you may need to find all these things and remove them.
