Sharpness

First of all it's great to see this tweenplatform adapted to JS, as many clients don't wan't any flash anymore :-/ I'm working on a site where the client asked for a shadow behind the texts, text-shadow isn't yet supported in GS12 I hope to see it in the future, particularly that the code is completely different in IE where I need to use an filter (shadow or glow). When animating a div with this shadow filter I got a black background during the animation in IE 7-9: http://sharpness.be/demo/201207_kodak/ It works fine in every other browser, does someone has a solution for this display glitch?