Opportunity Fire

[Rokko]

Hi there,

I am rather new to the John Tiller series and after some playing againgst the AI I believe I have a somewhat firm grasp on the major game mechanics.
One thing I don't quite get though is opportunity fire.
During my turn opportunity fire works just as you would expect. When my troops move adjacent to an enemy unit, often they get fired upon. Same is true when my troops fire at the enemy, often they recieve return fire.
However, during the AI turn, it appears as if my troops never fire at approaching enemy (AI) units. I don't think I have seen opportunity fire in such an instance even once. They do return fire when fired upon, but never at approaching units, which puts me at an disadvantage I'd say.
Is this intentional to give a boost to the rather poor AI or is there something I have to do to allow return fire?