Are there any benefits to having valid xhtml on your pages, besides knowing that all of your tags are closed and all of your special characters are escaped?
If your pages are valid it ensures that bots can crawl the page correctly and in turn could then slightly influence SEO. Although bots are getting pretty cleaver so it would really have to be coded badly before it took any real affect imo.
Valid XHTML, CSS or HTML means that Your site will appear correctly in all browsers. So yes it is important. Some exceptions to that are purely cosmetic. For example if You do rounded corners through CSS using CSS3 IE will see sharp corners, although I think Microsoft is currently working on updating their browser
Are you sure that is correct? It seems like more and more valid xhtml is broken in IE or maybe the validator is broken? I don't know...
For IE6 there is sometimes a need to add code that other browsers don't need, But IE6 is fairly rare. And to be honest people that still use IE6 aren't really the people I care to visit my sites. And W3C validator was broken. It's kinda of on and off. I wonder if they are adding the new HTML and CSS standards.
