Yeah, I've had it happen in the same 'battle' (same set of opponents* different battlefields) about half a dozen times in a row. It doesn't seem to be dependant on my character's actions as I've had it happen while I had my finger off the trigger so to speak.
CTD seems to coincide with an NPC being injured (and the blood appearing) but as the player character is the one doing most of the injuring it seems like you're causing it most of the time.
To take a wild stab in the dark (heh, pun) I'd say it might have to do with having too many blood 'stains' on the characters.
*Vagir Raiders
Also; the new version is about ten different shades of awesome, keep up the good work.
Edit: oh wow I didn't see the .711 update- quick work, very impressive.