There's only two ways to get animated themes.

1. Get them from a website that has animated themes as they will supply you with the theme and the software needed to make it work. http://www.astod.com/ has plenty of animated themes and allows you to create your own.

2. Make them yourself using Carbide UI.

Download Carbide UI here
http://www.forum.nokia.com/info/sw.nokia.com/id/bb173537-4e67-496f-9967-50917d5cfc47/S60_Theme_Studio_for_Symbian_OS.html

If that trick doesn't work, try to download OwnSkin program.When animated theme would be downloaded and set as main theme,then you have to go to OwnSkin into your phone,open that in settings theme animation set ON and press exit,should work,tried on Nokia N76 and N93i-working fine.