I have ,here, a quote from a google search. So you aren't alone   


Quote......
What you're looking at is the result in the difference in what character set your browser is interpreting, versus the character set originally typed into the form, saved in the database, or saved on the page. In other words, there's a discrepency in "charset". Below, I provide a checklist that should help in most situations.

I know when I first saw the black diamond with question mark, I was using a research tool I had created, which includes a script to pull and print some lines from another site. There were sometimes numerous "Windows" special characters in the page code of other sites. When I changed my Safari browser from default (which was set at UTF-8) to Western ISO Latin 1, the text was normalized; and I could read it.

That was a short-term, immediate fix. Of course, I, like you, needed a long term, permanent solution.

It's possible, as you thought, that the "wrong signals" are being sent by the server; but you should be able to correct this if you have control of the scripts on the server.


Some additional reading.. It's all greek to me, but it does explain more.


http://blog.salientdigital.com/2009/06/06/special-characters-showing-up-as-a-que...