I think that the place that you are getting those animations from,
Animation Factory, is doing something a little wierd in order to ensure that folks actually pay for their work. I can have two browsers open, side-by-side, and cut+paste the URL into both, and have one of them show the gif just fine, and the other give me a permission error. Ten minutes later, the other one might relent and let me see the gif there too.
The result is that I would see just a little broken gif box (box with red x) on your posts, then later on, come back and see the intended lady_news_anchor or Biohazardman gif on this thread. It'd be cheating to look for a way around this, so I'm not going there.
Whatever the reason, it's a total bummer, man. :o)