[Zope] structured-text unordered list is rendered wrong in zpt

[Max M]

I am rendering some structured text in a page template. The text looks 
like this:

test_text:
#######################################
Some paragraph

- This is a list item

- This is a second list item

- This is a third list item

A closing paragraph
#######################################

And it generates the following html.

#######################################
<p>Some paragraph</p>

<ul>
<li><p>This is a list item</p></li>
<li><p>This is a second list item</p></li>
<li><p>This is a third list item</p></li>

</ul>

<p>A closing paragraph</p>
#######################################

The problem is the superfluous <p> element around every list item. It 
makes the list item appear on another line than the bullet :-s

Does anybody know the problem is here?

The tal used to render the text is here.

#######################################
    <div tal:define="sfmt 
modules/Products/PythonScripts/standard/special_formats; sttxt 
nocall:sfmt/structured-text" tal:omit-tag="">
        <span tal:replace="structure 
python:sttxt(here.test_text)">test_text</span>
    </div>
#######################################


regards Max M