Disappearing elephants and chariots

I have experienced this problem now playing Seleucids, Egyptians and the British. Basically, I wheel out my undamaged elephant or chariot units to a fight only to find many of them have mysteriously disappeared. This problem seems particularly severe if said units are in a city under siege - and I am talking an immediate sally to break the siege, not hanging on for 5 turns just for the hell of it. Considering the costs of these troops, to suddenly have 15 elephants out of a unit of 18 vanish hurts! I even had one unit of war elephants reduced from 18 to zero! Go figure! I had the unit icon on my tool bar but none of our little trunked friends for all the effort.

Any body know what is going on here? Is this a recognised bug?

Many thanks. :help:

I could understand it if it was a long siege...

It's a bug. Any unit in a siege that has less than 20 men(on huge unit sizes) in it is usually lost after the battle wether they fought in it or not. Seems to be tied in with the withdraw bug. Also any unit that is routing when the battle ends in a city is usually lost also.

The withdraw bug has been mention many times and with all the reports on it, it should be fixed in the next patch