I've just started investigating this excellent data source and it seems that in my home country (UK) there are some significant population data errors. Take Alford, for example, lat 51.08833 lon -2.56417. This is a tiny village with a population around 50, but your data claims its population is 3321. Can anyone explain this or perhaps do something to address the mistake?
The problem appears to be widespread throughout the UK. I would suggest fixing it in bulk. Worldgazetteer has population data in it, which appear to be significantly more accurate.