[Zope] single quote is translated to <code>

I've upgraded to zope version 2.6.2, python 2.1.3. I'm using Zwiki version.0-11-0rc1 Now in some pages the single quote is translated to <code> and </code>. This produces errors in: <dtml-var expr="REQUEST.set('key','value')"> It didn't happen in the previous zope with the same zwiki. How can I prevent this translation? Wim