Previewing faq causes loss of teaser text

When answer text is entered and a preview request is made both trimmed and complete versions are shown, but the answer text contains just the body of the answer, whole, so if "save" is hit at this point just the body part of the answer is saved and the first lines (those of the teaser) are lost

My installation is a vanilla one of both drupal 6beta4 and faq module.I have added fckeditor module but with and without fckeditor I get the same results. No category is set.
The only change is "show teaser enabled" because without it if the answer is just some lines short ( like "yes") nothing is shown as naswer, but I guess it's the same problem, because it's always the teaser that get lost.
Teaser functionality is working fine previewing text using other content types like "story" or "page"