I WIN!! (crash)

I'm wondering if others have encountered this problem; I'm trying to understand what's happening:

I'm playing with the Senate and the Scipii removed from the game. The Julii are the sole Roman faction and I'm reusing the Brutii as another Greek faction. Playing as the Romans, I fight a battle to conquer my 50th province and win. On the strat map, my victorious general advances into the settlement. I WIN!! Game crashes. I'm crushed: the victory movie didn't play.

I was immediately suspicious that this was a problem with victory conditions due to fact that the Senate missing from the game. I replaced "imperator" with "take_rome" for the Julii in descr_win_conditions.txt. This also caused a crash, but on the turn after the victory conditions had been satisfied. Again, no movie. When I use the combination "hold_regions (blah blah blah)" and "take_regions 50", everything works fine. Victory movie supplies much-needed closure.

Trying to understand what had happened, I fiddled around with the Brutii. When I use "imperator" for the Brutii, the game doesn't recognize that they've won when they've conquered 50 regions (including Rome) but it didn't crash as I had expected. Using "take_rome", the game does recognize when the Brutii win.

Finally, playing as the Julii again, I tried giving Rome to the slaves at game start on the theory that "imperator" only works if your faction doesn't control it at the beginning of the game. Another crash. Lastly, I tried the same thing with "take_rome": this didn't cause a crash but it also didn't recognize when I'd achieved the victory conditions.

I'd be grateful to anyone who can help me figure out this puzzle.