
Just testing this.
EDIT: Right, it's working in the forum posts so theoretically (as I believe the HTML constraints are the same) it should work in your articles too. Note that it's small because the full-size image is pretty large! The code you'll want to enter is this:
<img alt="" height="X" src="http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Breakup_of_Yugoslavia-TRY2.gif/746px-Breakup_of_Yugoslavia-TRY2.gif" width="X" />
You'll have to change the height and width to something that'll suit your page best - I left them as X. They're the width and height of the image in pixels.
I hope this helps!
EDIT2: I've just checked in a drafted article and yes, the code will work however you'll need to click the "edit HTML source" button and place it inside a text module rather than an image module. I believe this is potentially causing the problem as I don't think the image module is built for .gifs.
EDIT3: Can confirm this was the issue - it seems that when you use the image module Wizzley re-uploads the image to their servers which is a sensible thing to do - it means that the image will always be available. This causes a problem when it comes to animations as it'll only upload the first frame of the animation. Using the HTML editor bypasses this as Wizzley displays the content as it is on the URL that you gave it which in this case has been uploaded to Wikipedia's servers as an animation.
EDIT4 (Lots of edits!) : A mirror is available here ( http://i.imgur.com/OIThO.gif ) which in all honesty may be more stable than the Wikipedia URL - I know WIzzley favours imageshack but my personal preference is with imgur for uploads. This would make the code that you want to use (don't forget to change the height and width!) :
<img alt="" height="X" src="http://i.imgur.com/OIThO.gif" width="X" />
The two bits of code will produce the exact same result it's just that this one is potentially more stable than the Wikipedia link though the admins may prefer the gif to be hosted via imageshack which isn't a problem - if it is a problem and you're unsure how to do this, just drop me a PM and I'll be happy to help!
Apologies for the long-winded reply and bajillion edits!