Has animation been removed from the site? I'm not sure if that's even possible, but I just uploaded this sig, and it's not revealing the animation? Its an older gif that I posted to a topic once, and thought I'd use for a temporary sig as I don't think many got to see it. Its Ross celebrating a victory with surprising stature I didn't realize he had, who's head morphs revealing a similar facial structure to Herman Munster. I pared the quality down to a more conservative size, which might have had an effect, but I tested it through my browser and it seemed to function properly.
