Windows 7 Dreams -- Fill Screen?

Forgive me if there is a topic on this already, but I can't find it! I have Windows 7 RC (and will be buying 7 later this month). The dreams run fine, but I can't seem to find a way to stretch the dream to the entire desktop?

I've even tried adjusting the stretch type in the Windows 7 Control Panel for desktop display, but no matter what I do, the dream has two black bars above and below (one the size of the 7 taskbar). When I displayed other static desktop pics before using Desk Scapes the picture would show through the transparent taskbar, and that's what I want. I don't want a black tasbar!

Thanks in advance for any help.