I think the issue is more with the tool we use for upload processing, rather than the size of the gif. It's pretty old, and I think just can't handle gifs that well - more useful for png/jpg.
I'll see if there's a newer version of it, but in the mean time gifs do work better in the animated gif thread, where it doesn't rely on our creaky old system
My e-peen is bigger than PJ's