I use a UK keyboard as well. First thing though, you have the UK keyboard in the 3rd position, it will default to whatever is in first position.
But yes, delete all the rest, and only keep the UK keyboard. I had an issue in the beginning as well, and it seems to be a Ubuntu problem since other distro's based on Ubuntu all had the same problem of the keyboard defaulting to U.S. I went in and changed some of the configurations files, (sorry, I don't remember which ones) and I've not had a problem since.