After the latest round of updates, I ran the lot through validator.w3.org.
First it came up with a missing </div> at the end of the page. When I added that, I got the following error.
Line 280, Column 1: unclosed end-tag requires SHORTTAG YES
However, there is a <body> in the line directly under </head>, and a </body> directly above </html> at the bottom of the page.
No typos that I can see, and I have even deleted both tags and retyped them. Nada.
Where does the error message in the validator stem from?