[ZPT] Sequence.sort & Page Templates in CMF1.2

[HoYin Au]

I'm having major problems with using sequence.sort in PageTemplates on
CMF1.2 + Zope 2.4.3 + Python 2.1.1.

The setup:
/portal_skins/zpt_custom/main_template defines the main template for the
site
/portal_skins/zpt_generic/index_html is the default view
/somedirectory/local_html contains the code with sequence.sort

The skin order is the basic ZPT skin, except with zpt_custom appended in
front of the list (i.e. "zpt_custom, zpt_generic, etc.")

Whenever I view somedirectory, I see a list of links in that directory
sorted alphabetically.  However, all the link to images on the page are
broken, and further checks reveal that Zope has gone for a restart.

However, it works fine when I call local_html directly (contents only,
no template stuff)

Any idea what is wrong?