So I created a skeleton part that is just a 3d sketch. ie Part1A

Then I created a new part and inserted the above part into it and used it to create my first part.  ie Part2A

All works and is tied together. 

I did a pack and go and it created a new folder with all the parts with the new name.  PartxB

However when I open Part2B it shows the first part is still Part1A?

Can Pack and go not copy of the inserted sketch?