I have a simple throbber, that is automatically shown when an ajax request lasts longer than 3 seconds. This throbber consists mainly of an animated GIF-Image. 

Now, I want to use the same throbber also for regular links, meaning that when I click a link and it takes the server more than 3 seconds to respond, the throbber is shown. 

Unfortunately, it seems that firefox is unable to play the animation, while it is "reloading" the webpage. The javascript is called and fades the throbber correctly in, but is it not spinning.

How can I make firefox play the GIF-Animation while it is loading?