This does seem to be one of the most confusing areas i've come across with international travel - I have been advised that the 90 day rule officially stands (as listed on the US immigration site).

Personally speaking I entered the US last November with less than 5 months on my passport and had no problems. In fact when I re-newed my passport it totally phased them the next time I arrived because they new that I regularly travelled but the passport number was different, and they suddenly had no record of me.... (thousand questions time)

Anyway, glad you got it sorted out, best of luck and have a great holiday.