Disable Sticky Header?

I am screwing around on a site located here:
http://66.147.244.78/~themuff3/
It is the AllAround theme.
How is the sticky header enabled or disabled? Usually most themes I use have a checkbox in the theme options admin to enable or disable the sticky header but this one does not and it is active by default.
Is it in the css or js or maybe I could just remove something from the header.php file?
I could style the smaller header that appears when you scroll to match the default header which is…
Disable Sticky Header?

See original post by bellcom