Yed, Version 3.17.2 on Windons 7 pro x64
When you put some elements from palette like Computer Network or People, they have the same type in the Current elements palette and only one representation in this palette.
So when you click right on the element in the Current Elements palette to select all elements same type all people and computer nodes are selected.
As a workaround, I put a different fill color (not displayed in the editor) to see each type of component in the Current Elements palette and I can select them with a right click.
I 'm not really sure if it's a bug or a normal behaviour.
Even with this , Yed is a very useful software