Bug? My assembly turned inside out to an Escher...anyone seen this?

Not a mate problem, everything is in the same position.  It's a graphics thing.  All the parts, I see the internal faces instead of the external faces.  If I click the part and open it, the part file alone looks fine.  Rebooted and it still does it.  I can't show a snapshot or the file as it's proprietary etc., but just wondering if someone has a fix so I don't have to rebuild the assembly.SolidworksAssemblies