The avatar I'm using is animated. It doesn't animate on SMF.
Can you make it so that SMF will work with animated .gif avatars?
First, a clarification: Animated GIF images work with SMF. If an animated avatar needs to be resized, the animation is lost. That's because SMF uses GD to resize images, and currently, PHP has no built-in functions that can resize animated GIFs and keep the animation. Once PHP provides those functions, it will be easy to implement. Until that happens, there's nothing we can do.
Animation works in SMF, as can be seen from my avatar. Just use gifs that are not larger in size than the allowed, so SMF won't resize it.