404 on intro-bg and downloads-bg when using project pages

[cdeil]

Thanks for making this theme ... it's great!

I'm now to making web pages and Jekyll, so apologies if this is just user error.

I'm following the instructions at
http://jekyllrb.com/docs/github-pages/#project-page-url-structure
and put this in _config.yml:

baseurl: /website-test

This works for CSS files, but I'm getting 404 not found errors for http://cdeil.github.io/img/intro-bg.jpg and http://cdeil.github.io/img/downloads-bg.jpg .

I think the issue is that here
https://github.com/jeromelachaud/grayscale-theme/blob/master/_includes/css/grayscale.css#L141
the baseurl config option is not taken into account?

    background: url(/img/intro-bg.jpg) no-repeat bottom center scroll;