All seems to have been fixed now. The BT forum site had users from all over the UK saying what had gone wrong, so from this we could glean it was quite a major outage. Now, the same folk, plus a few other geographically spread report that alls well that ends well.
1999 Freeserve Dial up --> Freeserve Anytime ---> 2005 Wanadoo 512k BB ---> Jul 2009 Orange up 8 Megs(hah!) --> Nov 2009 O2 LLU -> Nov 2011 BT Infinity( getting 37.5 megs now on ethernet)
Yamaha AW16G user
FujiFilm HS-10 User