Hi,
My family seem to be particularly difficult in census records. I have one family that is there for 1881 and disappears completely by 1891, I have not looked in 1901 for them yet.
I have another family that all have different places of birth and ages from one census to another, and another with different middle names. 2 of my G-Grandfathers manage to avoid being counted as do both of their future wives families.
Another one of them, a GG-Grandfather is proving to be a particular worry. He is Frederick John Mardon when he marries, Frederick Mardon in the 1891 census, born C 1876.
BUT in 1871 his family appear with a Frederick Mardon aged 13 weeks. By 1881 there is no Frederick, but there is a Fredrick aged 6.
My theory is that the child Frederick died and later there was another male child who was called Fredrick. As the years went by he began to spell it Frederick, and John was added at some time. I am currently looking for the BMDs to prove this, but to complicate it, this family moved all over the country in 20 years, with children born in London, cardiff, Bristol, Penzance and Devon.
And Fredrick/Frederick's mother was born in Jersey or Devon, take your pick.

If there were not so many matches in the 7 children, I would assume they were 2 different families.
Kazza.