[Zope] TAL that kills

Interesting problem. IN a ZPT the following TAL will always kill the Zserver processes. <p tal:repeat="doc container/docStore"> <a tal:attributes="href doc/getId" tal:content="doc/title_or_id">document </a> </p> any idea why? This is Zope 2.5.1 running on python 2.1.1 on FreeBSD. I've done a littl tal and none of it has caused zope to die like this.