Try saving it as a .png or lowering its size to 5kb. Every image/gif/etc I've uploaded above 5kb gave me errors but 5kb and below uploaded just fine without SMF's bitching.
I used Zloffs gif maker thingy and took some frames away, I cant get the gif size to be below 5 without it looking stufftyInstead its at "57.63k"
Whats that from?
Unhelpful question: Why do you want it to move like that? as though riding in a car over very regular bumps?
https://www.youtube.com/watch?v=YlEb3L1PIco
*coughing gag*