How to not display CCK fields in teaser?

Hi,

I just created a CCK field in the "story" content type. That field is idsplayed inside the teaser, which I'd like to avoid. I played with weights, but none of it made the field go away from the teaser, it only move above the node's body; what do I have to do to prevent this?

That's basically what I'd like to have:

   headline
   taxonomy terms

  node body (teaser)

  <!--break-->

  node body (the rest of it)

  CCK field

I'm pretty sure this is a FAQ, but I couldn't find a satisfying answer so far. The only approach I found is to mess around with templates like node.tpl.php (http://drupal.org/node/133236); I would like to yvoid this, e.g. to keep the theme updatable without losing the changes with every update. I hope there's a cleaner way?

Thanks & regards, -asbdpl