How come the wheel...

also..

"Firefox users have some additional options via an about:config tweak:

• In a new tab type **about:config **in the address bar and press enter
  
• In the filter field type animation
  
• In the results listed double-click on image.animation_mode
  

• In the pop-up box type in one of the following:

• none — will prevent image animation

• once — will let the image animate once

• normal (default) — will allow it to play over and over"