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.
Your presentations may have been created with a different version of PowerPoint or with a different font set than what your have installed. If you select only the superscripted character, what font displays in the font dropdown? If you choose Format>Font and uncheck the Superscript attribute, does it change to a normal number, or does the arrow just get bigger?