I always thought it was Gill Sans

( RedStar returneth, Fri 3 Jul 2009, 12:01, archived)

FONTMONG™ GOT UPSET AND DELETED IT

( Donkey Gums @mattcomedy, Fri 3 Jul 2009, 12:08, archived)

I think it's their own special variant of it,
you'd have to have a keen eye to tell the difference though.
( Moon Girl Technologies horrendous beanbag, Fri 3 Jul 2009, 12:08, archived)

I used to have the design specification of the logo on a lurvley gate fold pamphlet thing
that the bbc sent me, so I think you are right, and not a font mong.
( RedStar returneth, Fri 3 Jul 2009, 12:15, archived)