Arctic Warrior: have a look at playBunny's remark. it can also be that your firefox browser uses the same setting (regkey) to set gif animation that IE uses. so the setting can be inherited, even if you don't use IE.
you can try also a non-browser program that shows animated gifs, there's a load of free ones on download.com and others. that's just to check if your pb is somehow browser related or something else.
(Cacher) Si vous ne consultez que quelques uns des forums de discussions sur une base régulière, vous pouvez les ajouter à la liste de vos forums favoris en allant sur la page du Forum et en cliquant sur "Ajouter à la liste des forums favoris". (pauloaguia) (Montrer toutes les astuces)