Hello A.!
Animated gifs are quite an old format that is becoming less used over the Internet (it supports only 256 colors).

Just as in Evo 8, if you insert a animated gif file on your header this is merged with the header. The best way is to convert it into .SWF, flash file. 

There are many free tools on the net that give you the chance to convert your files from gif to swf.
Hope this helps!