fullsize header image not working anymore with 1.1.0

Hi everyone

I’m using a full size image for my site’s header.
The image is 1140×125.

I used the custom CSS described in this tutorial to remove any margins around the image and this worked perfectly with Pinboard 1.0.6:
http://www.mouseclick.com/tutorials-2/adjust-header-image/

See result on my site: http://www.musoc.de

When I upgrade Pinboard to 1.1.0 it does not work anymore.
I get an ugly white margin on top and bottom of my header image.

Does anyone know how I get the desired result with Pinboard 1.1.0?
For the time being I downgraded to 1.0.6 again.

Thanks for your assistance.