Shoutbox

I use 8.5 so I can't be 100% certain, but try this:

Change the background property back to what it was, and do this:

Element[ID=Atom(ai558)]
{
    Background:argb(0,255,255,255);
}
Element[ID=Atom(ai559)]
{
    Background:argb(0,255,255,255);
}

Thats for 8.5, so I don't know if it will work for 9.0.

EDIT: Do a search for the above btw. It should be near the bottom of the 1001 style.