Can not created thumbnails with Imce

After upgrading my webiste from Drupal 6 to Drupal 7 i can not create thumbnails with Imce.
I just to, while uploding images with fckeditor and imce, create the thumbnails so i had a large image and a thumbnail.

When i now try to create thumbs nothing happens, i don't get a error and there are no thumbs created.

The GDI Libray seems to be working well. On to other websites, Drupal 6 and sub-domains, everything works just fine.

All the permissions seems to be allright, i cant figure out what is going wrong.

Fouch