I noticed something odd about this map when you try to trap in the middle of the platform you could not see the trap., but from the stairs and below it you can see traps. I'm not sure if it's the lighting or the tile/texture used from it.
Most likely the map has a .gat tile set just slightly below the surface of the map floor thus allowing the trap to appear slightly below ground. This could be fixed if you were to open within Borf's Brow Edit Program and inspect the suspected area. I will look into this when I get a moment to see if this is the issue, but could you please first provide me with a little more information on what traps you are using so I may replicate any findings?