Axel,
Assuming that you're using the content plugin to add these buttons and have configured them in the JFBConnect > Social area:
Please verify that you have the 'Show in Frontpage View' set to None in the JFBConnect > Social > Content Plugin - Like and/or Content Plugin - K2 Like tabs. If you have this set to none, but the buttons are still showing in your article, you can also try setting the article ID in the list of articles to exclude.
If you're using another method to add the social sharing buttons or neither of the above options work for you, please let us know.
-Melissa