validate local html

I'm using the latest version of firefox. Pages that used to validate no longer will. I get the message: No Character Encoding Found! Falling back to UTF-8. The first lines of the file are:
 
<?xml version="1.0" encoding="ISO-8859-1" ?>
        <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
                "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
     <html xmlns="http://www.w3.org/1999/xhtml" >
There are no spaces or newlines before <?xml
 
What could be wrong?

Received on Tuesday, 3 February 2009 10:48:18 UTC