Automatic citizens' placement

[Nym]

As many players, I often prepare wonders or keep the shields already collected for another wonder I lost by building the palace.
Sometimes the palace is about to be completed before I get the adequate tech. So I decide to slowdown the production to avoid completing the palace and change the placement of my citizens to minimize the amount of shields produced (even if it results in a short decrease of the food storage). If for some reason the city population decreases (starvation or disease), my citizens are automatically replaced and the sudden increase in shield production is then big enough to complete the palace I do not really want to build.
Does someone know how to avoid this?

[Ethelred]

Whenever the population changes the governor has to to do something about it and the governor simply reavaluates all of the population. In most instances that is the right thing for it to do. This is a rather special situation you are dealing with, so all you can do is keep a watch on the city. Its important enough that you should check the city each turn while you doing this.