ORIGINAL: Gil R.
This business of "Sergeant" difficulty and its impact is NOT, repeat NOT, a bug. There is an error in the manual in which the bonuses are one level off from what the manual says. This was reported soon after release and discussed at the time (though obviously it was a while ago).
(Mr. Z, if this is not in your list of manual errata it probably should be.)
What I'm saying is that the AI is getting a bonus even at Sergeant and below. That was not happening before this patch. I'm aware that the manual is incorrect when it lists "First Sergeant" as the no bonus difficulty level.
edit: nevermind, it looks like it got sorted out.
/me needs to read the whole thread before I post. [:-]