I have standard Twenty Twelve theme installed with zero plugins (only Bubble SEO for testing) and clean WP install. The issue is double title everythere – on posts, pages, archives, main page. All plugin settings are default.
Site title: dev.ram108.ru
Site description: [ram108] Development Site
<title>dev.ram108.ru | [ram108] Development Site dev.ram108.ru | [ram108] Development Site</title>
<title>Page Example | dev.ram108.rudev.ram108.ru</title>