Check your gps coordinates
For the follwing site at least, the gps coordinates are wrong. I believe they should be 51.99082°N, 1.37282°W, not the figure you give below. I believe i have also noticed this with another site in the past.
Cheyney Manor House
Cheyney Manor, Barford, St Michael, Oxfordshire, England, OX15 0RJ
020 555 1234