XML Entity for "/"?

The forward slash is valid as is and does not need further encoding.

The only reserved characters are:

>
<
&
%

For even more XML entities - http://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references

I know it turned out this wasn't the problem, but I thought it would be helpful to mention that, in addition to bobince's answer, the Fraction Slash HTML entity ⁄ looks just like a forward slash. Just in case anybody reaching this page actually does want an HTML entity for something representing a forward slash.