Floatin/Layer Banner

Hello, I´ve created a Floatin/Layer Banner in flash cs3 using as2.
The problem I have is that I sent it to the webmaster that will upload it to the site and he says that, the animation has a background and it shouldn´t. It should only have the animation.

But it has no background, and the background color is set to white (#FFFFFF). I thought that was having no background.

Am I missing something?

thanks a log, Marcelo.