C'est un bon pays franšais, mais tres difficile a parle votre, uhm, language.
If your MySQL install is outdated, you need another way than the install script to install the tables. In the discussion you linked to you see what and how the tables are setup. You're on your own there, install the tables manually with phpmyadmin or any such software, if you have that installed. If not you have to do it via the hardcore commandline.
The error you're receiving - seems your images and thumbnails folders don't have the right permissions. Under the general info tab in adminpanel, you can see if the folders are writable.
Check that and see what it says, either it says the folders are writable (both must be) or it says they are not.