I noticed a little bug. In page.css the target is set to h1#site-name. In the generated file that the theme settings makes the target is #site-name. That means h1#site-name gets priority and the theme setting for site name doesnt work, at least not in firefox. When I renamed h1#site-name to just #site-name in page.css, the settings works again. The problem is also on site-slogan, which is h2#slogan in page.css. Just remove the h2 and the theme setting works.