Early in one compaign, I lost a unit from a very-nearby kingdom took my still-undefended capital. There was no warning on the screen when this happened, which might be an issue but is not my main issue.
Took it back in a few turns an played along until it noticed that I hadn't had any new techs for a while. Then the reseach screen turns until next discovery was some huge number that filled the whole field. New game time.
