Hi, i found a problem in breadcrumb extension.
The home URL is wrong. That happen because i use the home url in other place, in admin options. Eg:
WordPress URL: site.com/wordpress (this URL is returned, instead of home URL)
Home URL: site.com
The problem can be resolved replacing get_site_url() with get_home_url().
This is located in wordpress-seo/frontend/class-breadcrumbs.php on line 72.
I hope this can help...
WordPress version: 3.4.1
WordPress SEO version: 1.2.5