I no longer subscribe to ancestry.co.uk and thus cannot give a precise example. However, in at least one year in the the IOM census, the place of birth was often described as Rushden, certainly in the printed transcription, and possibly in the handwritten one. I do not recall which years were so afflicted.
It was particularly annoying when trying to track down someone whose place and date of birth were known but whose name may have changed.
Presumably you never came across this in the copies that were used to prepare your census books some years ago.