Comment 5 for bug 1101402

that's right, since I'm using Kubuntu (KDE), I (wrongly) assumed that I didn't have to install gnome package but I forgot that Gimp is using gtk libraries

and indeed, after installing language-pack-gnome-fr it works!

as a side note, it is interesting to see the different approaches between Debian who chooses to install all language within each package, and Ubuntu who prefer to have all localisations/translation for all packages but on only the desired languages

thanks