TOC issue - (Superscript)

Hi there.

I am having an issue with my Table of Contents.  All my links works except for the items that have a superscript in them.  In the example below, when I create the PDF and hover over the items the three words of (Modes of Operation) are hot links that take me to page 26.  When I hover over the second entry I²C Digital Interface the only item that is a hot link is the letter I.  Our goal is to have the entire entry a hot link for customers to hit and go directly to the page.  I think the superscript is breaking the link.

Example below:

Modes of Operation .........26

I²C Digital Interface ............28

HELP!!!