ADE XL netlisting error (some schematic components are blank)

I have a simulation that isn't working with ADE XL - whenever it netlists parts of the netlist have no connections.  I am using standard cells with predefined connections in them and have some schematic parts that are made with symbols for the objects (standard cells) but the netlists created with those parts are empty.  Some parts only have the instance names, no connections, and other parts are fully defined.  Are there any options I should be looking into?

Thanks