I'm not sure what you mean by the position is altered but it sounds like you've got it now. Just in case, here's an anaolgy.
When you make a component it's kind of like wrapping the selection in clear cling wrap. Think of a sandwich wrapped in cellophane. If you want to make a change to the sandwich you have to open the wrapper. In the same way, if you want to edit a component, you have to open its wrapper first.
Now, if you have two individually wrapped sandwich components and wrap them in another piece of cling wrap, you have a nested component like the Shapes component in my example. If you want to wrap a pickle (the cylinder) up with the sandwiches, you have to take the pickle from where it is and place it inside the wrapper. In SketchUp Edit>Cut and Edit>Paste in place do that. So does grabbing the pickle and dragging it over the sandwiches in Outliner. Outliner is opening the wrapper automatically when you hover over it's name and it highlights.
And of course because the wrapper containing the two sandwiches is a component all other copies of it get the pickle, too.
All of this can be confusing until you have a really good picture of what's happening. Then you'll find it is all incredibly powerful.
