Thanks cowski. Found the setting to automatically populate the Model("Solid") reference set (see attached photo).
Starting to understand reference sets...used to hide things (like sketches) you don't want in top level assembly...
Thanks! Parts show up when I change Reference Set -> Entire Part. Previously, it was set to Model ("Solid").
Not sure why my geometry isn't getting automatically loaded into Model ("Solid")...
Parts are not visible when added to assemblies (NX 9.0.3.4) per attached screenshot.
-I've tried View -> Show & Hide -> Show All. Also checked that all Layers are visible.
-Parts are visible when they are selected as the work part, but not in the top level assembly.
-Also tried View...