If you animate an image that has pure black inside it. You will likely see white pixels appear in those places where it was pure black. I have only seen this appear in IE6 so far, and could possible occur in other IE browsers.

Here is an example of the problem:

http://originaltravel.co.uk/latin-america-and-antarctica/brazil/bahia/alcinos-pousada/

Either wait for the second image to fade in or out or click on the button in the controls to see the problem.

Applying a background colour to the image hasn't worked, and all that is happening is a simple animate({opacity : "show"})