My thoughts on the domination "problem".
I believe the strategy book states a 66% territory occupation is required for a domination win. IMO, this should read an AVERAGE 66% occupation is required.
This is will explain why a domination victory isn't automatic once you obtain the 66% during the game as the game averages out your territory over the number of turns.
I've read somewhere that the map size needs to be multiplied by .5 to get the actual number of squares allocated to your world due to the diamond shape. A standard map of 100 x 100 would really have (100 x 100) x .5 squares or 5,000 (not 10,000). With a 70% water allocation this means that 30% would be your world size - 1,500.
When you refer to the histograph it provides your average territory occupancy therefore you can always check your progress during the game. This could also explain why you can sit on 80% of the squares for some time waiting for your average occupany/zone of control value to increase.
I've only just thought of this and haven't had time to prove it yet. Maybe someone is in a domination game now whereby they might want to try this and report back.