Background Manager

I try to update my site by using background-images.
But they don't should be static, for this I found this great plugin:
http://wordpress.org/extend/plugins/background-manager/

I have activated the plugin, but it don't work automaticly.
So my first question, how and where in Atahualpa Options can I put a static background image?

And next, how is it possible to add such kind of a background plugin with automatic image-switch into atahualpa? This theme is absolutely great and I hope there is a possibility to do this with this plugin.