I am not having a problem with the game crashing randomly, however it still builds up memory usage on bigger maps with more opponents. I find a memory defragmenter is very useful when used with this game. I use System Mechanic's one but that costs, I'm sure there is a free one that does the job. What I do when the game starts getting a bit slow is save the game (which can take a while) and then quit and use the memory defragmenter.
However, you are talking about it crashing on a certain turn. I have only experienced crashes or stalls when it slows to a crawl then stops with too much activity, or sometimes when alt-tabbing and another window appears on top of the LH window. There are so many configs that some people can get crashes all the time and some rarely if ever.
AFAIK, I have not had the problem with the files corrupting. Are you sure your hard disk is alright?