Tom, I don't see it either.
A doctype declaration tells the browser what schema to use to render the page.
If there is no doctype declaration, a browser is forced to render the page in Quirks mode,
which makes it appear to take longer for the page to download, but
in reality it's just that it takes longer for the browser to display the page
because it has to wait until all of the content is cached before it can parse the html and display
the content.
Internet Explorer, much to the chagrin of FF and other browser fans, is very forgiving
of a lack of a doctype and will normally render the page as you want it.
FF and other browsers will not.
Additionally in newer editors such as Expression Web and SharePoint designer,
the doctype declaration drives the editors intellisense, in code view, to alert
the user that there is invalid html and or css declarations in the page.
Not knowing the content of your web page I would recommend adding the following doctype to your page
in code view at the very top, above the opening <html> tag.
It's a fairly generic doctype declaration:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"
http://www.w3.org/TR/html4/loose.dtd">
--
Steve Easton
Microsoft MVP FrontPage
FP Cleaner
http://www.95isalive.com/fixes/fpclean.htm
Hit Me FP
http://www.95isalive.com/fixes/HitMeFP.htm