I had the same problem but the solution was in the browser settings:
Enabling Animation on Internet Explorer 8 or 9
Step 1: Launch Internet Explorer.
Step 2: Click the Gear (Settings) icon in the –top right corner of the window. It is located beside the Favorite icon and below X-button.
Step 3: Select Internet Options.
Step 4: Under Internet Options window, go to Advanced tab.
Step 5: Scroll down and find Play animations in webpages* under Multimedia.
Step 6: Put a check mark on it. Multimedia Setting options on Internet Explorer 9
Step 7: Click Apply then OK.
Step 8: Restart Internet Explorer.
Step 9: Drag a gif image file from your hard drive to Internet Explorer. The animation should now be working fine.
Note: This solution applies only when animation setting on IE9 is disabled which is the main cause for non-playing animated GIF files. If it doesn’t work, I advise you reset IE’s current settings to default and it might help as well (Internet Options – Advanced – Reset…). Do that if only if you made changes to IE’s settings before.