JQuery Dither on Animation

I have a problem with certain jquery effects that I'm currently displaying on a page.

I'm not an expert at coding so I modify whatever I can with what is already available and see how it works.

This is开发者_StackOverflow中文版 barely noticeable, but if you go to the page http://www.expresscomputers.net/webservices and click on any of the images, you can see this dither that occurs on the rest of the images (especially the rounded blue one) which disappears right after the toggle effect is complete.

I have been trying to figure out what is causing this ditcher but have so far no clue! Could it be CSS or the effect itself?

Any help or a nudge in the right direction would be appreciated.

Try using PNGs instead of GIF images