The image script url is http://geekeo.fr/extensions/pun_antispam/image.php

The error message displayed there is the following:

Internal Server Error

Directory "/home/geekeo/www/extensions/pun_antispam" is writeable by group

Apparently you use pun_repository and it sets permissions for extensions directories to 777. But running scripts from a directory with such permissions is probably disabled by your hosting admins.

Now you can uninstall pun_antispam, remove it from extension directory, then upload it manually by FTP (not via pun_repository) and finally install it again.

Actually it's a question of server settings. But we'll think how to avoid setting permissions to 777 in pun_repository.

Yes. It solved the problem!

The error message displayed there is the following:

Apparently you use pun_repository and it sets permissions for extensions directories to 777. But running scripts from a directory with such permissions is probably disabled by your hosting admins.

Now you can uninstall pun_antispam, remove it from extension directory, then upload it manually by FTP (not via pun_repository) and finally install it again.

Actually it's a question of server settings. But we'll think how to avoid setting permissions to 777 in pun_repository.