Bad luck about the king teleporting - seems you have the solution now.

Other factions kings teleport too - and not just to capitals. I've chased the HRE up into a cul de sac in Friesland, and lo, when I invade he turns up in Swabia next turn. Same thing with the Sicilian king - he's invaded and captured a Serbia that has no port. When the counterattack into Serbia is done he's teleported through my fleet in the Adriatic (fleets and Sicilians being another subject) and reappeared in Naples.

Has anyone else noticed similar?