Does the 3.4.2 Dashboard have Chrome Frame headers?
From wp-includes/vars.php: if ( isset($_SERVER[‘HTTP_USER_AGENT’]) ) { if ( strpos($_SERVER[‘HTTP_USER_AGENT’], ‘Lynx’) !== false ) { $is_lynx = true; } elseif ( stripos($_SERVER[‘HTTP_USER_AGENT’], ‘chrome’) !== false ) { if ( stripos( $_SERVER[‘HTTP_USER_AGENT’], ‘chromeframe’ ) !== false ) { if ( $is_chrome = apply_filters( ‘use_google_chrome_frame’, is_admin() ) ) header( ‘X-UA-Compatible: chrome=1’ ); $is_winIE = ! $is_chrome; } … Read more