There seems to be some sort of an item bug or possibly a unit bug that causes the game to crash when you enter battles. I was going into battle with a group of forest bandits, this being the 6th battle with them or so, and now the game crashes whenever I try to charge the enemy.
The group can be 26 bandits or 49 bandits, haven't tried other enemies (hard to find other enemies). I had about 20 troops at the time. Couldn't be my number of troops as the problem, since I had a battle with 200+ ally troops vs. 36 enemies (few of my own, but still).
The game had been running smoothly up to this point, and I was using Direct X7 rather than X9.I can try and work out which equipment or unit it is tomorrow, if you'd like me to (or if it's some other problem if I can work it out).