Problems with the new Live Preview for WordPress 3.4.1

I’m having CSS issues with the new Live Preview feature that allows you to customize certain aspects of your theme.

It seems to be overriding my headers css whenever I choose to remove the background image that is in the Live Preview customizer with:

#header {
background: url() no-repeat;
}

And here’s my original CSS for the header that keeps getting overiden:

#header {
background-color: #959CA1;
background-image: url(images/hdrbg.png) !important;
padding: 0 60px 0 60px;
height: 141px;
overflow: hidden;
}

You can see the problem i’m having with the Header DIV block here:
https://widemanmgmt.com/newsite/

Please help me out as I can’t seem to find a solution to this problem anywhere, and I also can’t find where it is saving these CSS modifications to.

Thanks in advance,
Andrew