Quicknav gadget has display problems

When adding the Quicknav Gadget, it doesn't display suggested results correctly. In both the preview window and in the saved page, the suggested results look like this screen shot:

The same behavior occurs in Firefox and Chrome. The width of the odd display area corresponds to the width of the text.

Steps to reproduce:

1. Edit or add a new page
2. Attempt to add the quicknav gadget
3. Start typing search terms in the preview. Note the odd display.
4. Save the page with the gadget
5. Start typing search terms in the quicknav gadget. Note the same odd display.