Just to clairfy, the flights are not sold-out, they are just waitlisting and nobody clears the waitlist.
I have made my comments to BA this afternoon and the 'phone has been red-hot.
It would appear, the BA CDG staff close the busy flights to new bookings (from BA), and never re-open them. Everyone just sits on a waitlist, unless they show-up sufficiently early at the airport ticket-desk.
My friends in BA in London are not amused.
My favourite quote "I don't think they understand the difference between waitlist and stand-by, or if they do they are getting their priorities wrong".