WordPress kills an IFRAME's apostrophes

I'm using an IFRAME to let multiple sites embed one interactive element. On the IFRAME's actual page it works fine, and it looks fine on another website I embedded it. But when I embed it in a WordPress blog, all my apostrophes show up as squares.

I tried removing all smart quotes and apostrophes with "dumb" quotes, no luck.

I tried replacing all the apostrophes with开发者_如何学编程 ' and, again, no luck

Any clues what my cause this?

The IFRAME code:

<iframe
  src="http://necir-bu.org/wp/interactives/sheriffinteract/interactive.html"
  name="interactive" scrolling="no"
  frameborder="0" marginheight="5"
  align="center" vspace="5"
  widtha"590px" height="720px"></iframe>

And you can see the interactive code by just viewing the first link

This looks like an encoding problem. You probably should configure your blog to use the UTF-8 encoding.

Try adding the following to your .htaccess file:

AddDefaultCharset utf-8