My SIL happily told us all how their son (who is a teeny bit younger than my DS2) slept like a fairytale. I stayed with them and their son woke up and cried and was left. Sometimes what people say isn't exactly what goes on in reality.
Oh my, sounds just like one of the mums at DS2s childcare centre. She came in saying that he was "sleeping through" now. What that actually meant was that he had reached the "appropriate age" to go without that extra night feed and was left to cry it out until the "appropriate time" which was 7am!! Go figure?! Some peope read these guides and take them literally!