Not Valid?

I am running into a problem where I try to validate a my css and the 
validator complains that my xhtml is not valid.

OUTPUT:
--------------------
Target: http://www.rebeccahales.com/contact.php

Please, validate your XML document first!

Line 68

Column 53"

Element type "null" must be followed by either attribute 
specifications, ">" or "/>".
----------------------
END OUTPUT

Yet, running my xhtml through the xhtml validator reports that my xhtml 
IS valid. The url in question is:
http://www.rebeccahales.com/contact.php

I am getting this problem on all this site's pages and it seems to be a 
result of something in the footer.

-jared