This would be a support type question, but let's see... compare the size of the gif's dimensions (right-clicking and going to the Properties when viewing the file) and make sure it is not bigger than 145 by 96 pixels. If it is, then it might've re-sized it down without converting the entire GIF animation.
If you are wondering how to re-size the GIF file, there are programs available out there, JASC animation shop being one of them if my memory holds true.
