This is the reply I have received from Supporter Services following my email earlier today:
"Away ticketing has changed slightly, we now go on sale to supporters earlier to allow us to get a better understanding of the volume of supporters wanting to book for this game which in turns allows us to choose an allocation from the home club.
As we are now on sale at an earlier time, the reason behind us not being able to choose exact seating is because we do not get the home clubs seating plan until later than usual meaning that we cannot select seating at the point of purchase."
So it sounds like tough luck guys - you can buy tickets early, but don't expect to have anu choice asa to where you sit
Perhaps they could introduce a preference (Lower/Higher) for those who prefer to be sat down the bottom and those who prefer to stand near the back or even allow a block preference. That way they can get a better grasp on demand and we can attempt to please those who have a preference..