${...} breaks rendering of {{code}}

http://wiki.cloudbees.com/bin/viewrev/RUN/Configuration+Parameters?rev=20.1 (using 2.0 syntax) displays odd rendering in the first code block. The source is

{{code}}
<?xml version="1.0"?>
<cloudbees-web-app xmlns="http://www.cloudbees.com/xml/webapp/1">
    <!-- context parameter -->
    <context-param>
        <param-name>accessKey</param-name>
        <param-value>${key}</param-value>
    </context-param>
...
{{/code}}

which renders normally except for the XML tags with dashes (-) in the name, which render in a box:

<span style="font-weight: bold; color: #008000; ">&lt;context</span>
<span style="border: 1px solid #FF0000; ">-param</span>
<span style="font-weight: bold; color: #008000; ">&gt;</span>

The presence of the character sequence ${ seems to trigger this odd behavior. Tried escaping with backslash and tilde without effect (attempted escape characters rendered). Inserting a space $ { disables the problem, but of course the space is rendered in the HTML output too.