The UTF-8 meta tag you have in your HTML source may be overruled by a content type header sent by the web server software. Headers sent before the HTML source have higher precedence than meta tags. You can check this with a server header checker. There are tool websites which offer that functionality (WebmasterWorld has such a header checker in the subscription area for example), or you can use the Live HTTP Headers add-on for FireFox. The way to change this header differs depending on the server software (Apache, IIS, Nginx) you use.