news - unexpected behavior

[mox]

Hi,
without warning, the behavior of news model is following:
when I go to the page of the news I see the summary both in the div with {content} and in the div with {cms_module module="news" category="post-t"};
when I click on one item the duplicate summary it disappears in order to leave the place at the details of the news
what happen?

thank
mox