I gave this one more go and instead of putting a false house number used "underscore" key (i.e. _ ) and it seems to have updated ok, but my address now has _ in it.
I also have a similar problem of a house with no number (we live in the country) so the system wont accept a name but wants a house number. Whats odd is its a change due to a new credit card , so the address is all in there. One thing you can do is s...