[VE][63] Error Message Feedback

Validating http://www.v-1.co.uk/new_site/index.php
Error [63]: "character data is not allowed here"

Hi I've got a problem with 4 sites.

Yesterday they all validated fine as Strict, but today they have all 
come up wit errors, did something happen over night in the verification 
of web sites?

The one is listed above the other two are:

http://www.johnmiller-prints.com/enterprisingcards/index.php

http://www.bulwellvision.org/testing.php

http://www.hearsonholidays.com/testing.php

Really can't understand how they've become invalid?

Please help, as I'm trying to make all my new sites verify as strict!

Kindest regards in advance
Glynn