Thats strange, I haven't experienced this except in sim city 4 deluxe, must reload after every save or it will CTD after a while. I wonder if it has something to do with Steams way of saving. Have you tried to delete and redownload the mod or game, although if you're not experienceing other crashes I would leave it because Steams downloads sometimes have problems. Have you looked at the HWRM.log file or the Error.txt file after a crash? Play a match and save multiple times without reloading and let it crash, then post these logs here, could tell the developer something and help you.