XHTML 1.0 with content="text/html" is "tag soup" since you are using XHTML doctype and XHTML coding methods like lower case tags and closing with /> instead of > but a few lines later you are telling browsers to process it as HTML. It doesn't really matter, but it's a mixture of two methods.
Since he wrote that we now have HTML 5 in beta form which you can use now, and pure XHTML with content="application/xhtml+xml" which you shouldn't use for normal websites.
Read this too:-
Note that http://dev.w3.org/html5/spec/Overview.html in Item 1.6 HTML vs XHTML in the W3C HTML 5 page says The first such concrete syntax is the HTML syntax. This is the format recommended for most authors. It is compatible with most legacy Web browsers. If a document is transmitted with the MIME type text/html, then it will be processed as an HTML document by Web browsers.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.