I remember in one game as Denmark, i annexed Meckenburg and Pommerania. When i annexed one of those, and when they had an army besieging one of my provinces, suddently the army disapeared, but for some wicked reason, a 0 men army kept besieging the province for ever, that is, until i marched with my army into it. It is really annoying. It was long time ago, i even think that that army looted my province (grrr!). I am too lazy now, but i will post the screenie soon. This makes me remember the 0 army tank bug in hoi1. The tank could go from Paris to Moscow in like 5 days, conquering all the provinces along.