Maybe you've heard this pergunta before but... (Animated icons)

The first dia i heard about the animated icons, i uploaded straight away, it is currently my usericon and it worked fine. Today, i decided to change it, but when i tried, only a picture came out (It wasn't moving). I have a folder with a whole bunch of animated GIFs so i tried them all to see if any worked, they didnt. I check to see if it were the actual icons, so i re-uploaded another copy of the one i have now, and it came out a picture...so it wasn't the file..So now i'm confused...Why isn't it working..Is this happening to you?..