IFrame Gotcha not caught by VS05 parser

The VS'05 script parser is pretty good at catching tag violations when you work in the html view of an aspx page. However, it did not catch the need for an </iframe> closing tag for the iframe element. This is a requirement for the iframe tag in both IE and Mozilla. I didn't know that previously, and was getting the strangest results when I would inspect the DOM and find that everything below my iframe tag was consumed in the enclosing div.