You seem to be having an abnormally large number of odd events occurring in combat. I've seen a couple of them in my own games, but not on any sort of a regular basis.
The Spaceempires5.com board has more active PBW users more familiar with the nuances of strategic combat strategies and probably could help clear up some of the issues.
I've come to the conclusion that while there are some bugs, some of the issues I ran into were due to misunderstanding the tactics (and in particular the "target type"). Thanks for your help guys! Enjoying the game quite a bit now.