I think the post-battle CTD is a pretty well known issue. I've noticed that these kick in more after I've been playing a while - the first few battles I have in a session are fine but sooner or later a CTD will happen after a battle. I've always thought it was EB's way of telling me to go to bed...

Completly unscientific I know but it seems to me that there is a much increased level of hard drive activity during a battle which suffers from this. If the hard drive is whirring away during the fight, then a post battle CTD often follows. I'm going to try rebooting the system after every hour of play - if these post-battle CTDs are linked to how long the session is then this might go some way towards minmising them.