Yeah, that's a funny story, although I'm sure I wouldn't laugh if I had to hear that warning during my flight :).
It was reported to have gone off into 3 hours after take-off. That means, provided the asctual flught status was okay, the plane was on cruise and on its corresponding altitude and speed. Now, you guys - aviation specialists of different kinds - I bet that if any of u were on that flight, and u heard the message, u'd start to suspect somethting wrong - I mean - you're flying straight, at about 10kms above the earth, everything seemed fine and then that message goes off.... Must be a bogus...
Anyway, BA is indeed the World's favourite :).
Scotland - Russia