https://www.icyphoenix.com/viewtopic.php?f=26&t=6874&p=47238#p47238
-----------------------------------
Mighty Gorgon
Sat 23 Jan, 2010 10:35

Re: GIF: Not Every GIF File Is Moving!
-----------------------------------
Unfortunately when GIFs are resized via GD Libraries the animation is lost. You can still see the animation for those pictures which are smallest than the thumbnail size (set in ACP) because they don't get resized.

There is nothing to do... only way is increase the thumbnail size, or try to change settings in ACP regarding GIFs... try to have a look around.

[b]Show GIF thumbnails without using GD libraries (full images are loaded and then just shown resized).[/b]