So when you say you have the pasability set correctly do you mean the layers.
Meant for tiles that can be walked over. Lowest layer. Appears under everything else.
Meant for tiles that don't allow you to walk through. Second layer. Appears above the 1st layer and below the 3rd layer.
Meant for tiles that allow you to walk behind but not through. Third layer. Appears above all other layers.
Meant for events that do stuff. Event Layer. Appears above First and Second and above/below Third depending on the pasability settings.
Hope that cleared something up.