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's almost certainly a font issue. Chances are that the presentation uses fonts that are on the laptop, where you created the presentation but not on the tablet. As a result, when you open the presentation on the tablet, PPT substitutes a different font (with different size/spacing) for the REAL font that it's supposed to use. Then when you fix it and move it back to the laptop, PPT once again uses the REAL font and that whacks all your spacing again.
Choose a font that you're sure is on both computers and the problem should go away.