Special characters showing as funny letters inconsistently

When I test the page below, everything displays normally cross-browser and on different OS’s, but my client showed me a screen capture where the special characters displayed as funny characters. Any ideas what could be going on here?

http://www.cynergydata.com/products-services/vimas/

Are you using DOMDocument() and loadHTML() on content somewhere (either in your template or your functions.php file)?

If so, you will need to use this on the content:

mb_convert_encoding($input, 'HTML-ENTITIES', 'UTF-8')

or, when using loadHTML():

[COLOR=#000000][FONT=Consolas]$dom[/FONT][/COLOR][COLOR=#000000][FONT=Consolas]->[/FONT][/COLOR][COLOR=#000000][FONT=Consolas]loadHTML[/FONT][/COLOR][COLOR=#000000][FONT=Consolas]([/FONT][/COLOR][COLOR=#000000][FONT=Consolas]mb_convert_encoding[/FONT][/COLOR][COLOR=#000000][FONT=Consolas]([/FONT][/COLOR][COLOR=#000000][FONT=Consolas]$input[/FONT][/COLOR][COLOR=#000000][FONT=Consolas],[/FONT][/COLOR][COLOR=#000000][FONT=Consolas] [/FONT][/COLOR][COLOR=#800000][FONT=Consolas]'HTML-ENTITIES'[/FONT][/COLOR][COLOR=#000000][FONT=Consolas],[/FONT][/COLOR][COLOR=#000000][FONT=Consolas] [/FONT][/COLOR][COLOR=#800000][FONT=Consolas]'UTF-8'[/FONT][/COLOR][COLOR=#000000][FONT=Consolas]));[/FONT][/COLOR]