I believe there is a error in the web_menu.sitemap XML file.It should display the Home page as the first element in the navigation menu, however it seems there is a missing siteMapNode at the start, so it's treating the home page declaration as the first/top level node incorrectly and therefore doesn't display it.
The first 2 lines after the siteMap entry should be:
<siteMapNode>
<siteMapNode url="~/Default.aspx" title="$resources:Kartris,ContentText_Home" description="$resources:Kartris,ContentText_Home" />