XMLHttpRequest: send(data) does not set correct Content-Type header correctly when data is DOMString or Document. Per the XHR spec: If data is a Document Let encoding be the preferred MIME name of the character encoding of data. If encoding is UTF-16 change it to UTF-8. Let mime type be "application/xml" or "text/html" if Document is flagged as HTML document, followed by ";charset=", followed by encoding. If data is a DOMString Let encoding be UTF-8. Let mime type be "text/plain;charset=UTF-8". Test: http://tc.labs.opera.com/apis/XMLHttpRequest/send-content-type-string.htm
*** This bug has been marked as a duplicate of bug 11049 ***