I think it's because the month is named after Augustus so strictly speaking August isn't really a month name, not like February or October.
Also, August is not originally an English name but Scandinavian, Polish and German where August is just a name (and stricly male) and not a month. It's a coincidence, I believe, that August also is a month in English and because of that seen as a unisex name.
This message was edited 3/17/2009, 12:31 PM