One thing to check is that all countries ack is set to the same lethality, if one of them is not a .7 this could be causing a problem, as we have seen in other set up's.
Maned 5inch is always a killer, some of you may be experencing this, as to the Auto ack, the Flack is generaly just eye candie, unless the seting is screwed up, at .7, like sabre said, Flack does virtualy no damage, more Ships dont seam to effect this much, while their is more of it, it is still just eye candie.