i tried this with my Red and my Chrome themes. It just made it black instead of transparent. And I mean.. I made the background .9.png images transparent. I'll try again with Gold which I am working on as we speak.
think i narrowed it down a bit if the phone.apk incall gradients are transparent the phone brings up the a xml background color just dont know which one it is i think its the one that changes the bg of the usb as well
i was working on this one not to long ago i think i may revisit it tonight