Settings of GF not applied

Hi

on one of my sites,,i get constant error like this :
Please select both a thumbnail and slide presets in your Gallery Formatter settings for field_diapo_lycee. The jQuery gallery needs these settings to work.
so i go to admin/content/node-type/actu-association-revue-presse/fields/field_diapo_lycee as mentionned, but there settings are good re-save the page doesn't change anything.

in admin/content/node-type/actu-association-revue-presse/display, i set jquery gallery,
i use image field to upload images and display them via view using the galleryformatter plugin

what can i do to fix this ?

thanks