I run into the same issue. I have a new iMac with everything upgraded (faster processor, maxxed out ram, upgraded graphics card, etc.) and still, when my wife and I play hot seat, we will frequently run into crashes (by frequently I mean every 2nd or 3rd game will end in a crash). I haven't tried uninstalling and reinstalling, but I'll give that a try. It's very frustrating. On a side note, I use the steam version of the game (just switched to Mac in April, had it for PC before that).
*edit:
Uninstalling the game on a Mac simply means deleting the file from "Applications" right?