Hah! I did and was never so unlucky! See it depends on what map you are playing. If you are playing a map where you are squashed in with other civs, culture flipping can really be a pain.
I don't play for cultural victory, currently it is rather boring. Perhaps it will become much more interesting. As far as learning how it works, that will go for all of us. The same goes for the rest of the new features. I will certify this, we will all master them in no time.
Now the question I have with culture flipping is, is it border flipping or city flipping? If it is city flipping they must be out of their minds. Cities should not change hands through culture, but through war, or trade. For the most part war. To change this now is rather odd. If culture affects cities it should be through immagration and population, reduction of happiness perhaps, but not ownership. That is how I see it anyway.
It's been a long time since I've played Civ 4 with KMod, but from what I remember opposing cultural borders aren't much of an issue when you conquer your opponents anyways .
From what I've read, in the new expansion, you only get unhappiness when another civilization has chosen a different ideology than you and their culture, or tourism score is higher than yours.