A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
It sounds as though you're pasting directly rather than choosing Paste Special and then Link.
Things may also behave differently if you have an empty content placeholder on the slide when you do the paste or paste link. I'd make sure that any content placeholders have content in them first (even if only some dummy text) or simply delete them.
Steve Rindsberg PowerPoint MVP