In this zipfile there is one IFC file with 4 IfcSlab entities. Only the first IfcSlab generates geometry (but it's not a solid as it's supposed to be). The other 3 don't generate any geometry (in the BIMserver plugin there are no IfcOpenShellEntityInstance objects generated).

Both Solibri and DDS-CAD open this file the same way, both seem to be as expected. Also tried in Blender with version 0.5.0p2 of IOS and the same result (only one object visualized).

IfcSlab-1.zip