I don't have Hidden Springs yet; was wondering if that could be a cause, as I have considered getting it. The problem I am having is in Riverview, where my family has grown. I am noticing it when I have a family over three, and a lot is going on.
Am going to follow the suggestion to save the game in the save as instead of save and quit. I lost a family due to the freeze up. In one family, Mom and child just froze, no matter what I tried, quiting, removing everything around them, and a couple of other things, they were frozen. The maid just walked around them and did the housecleaning.
With the problems that Hidden Springs seems to have I had wondered if that could be a factor and would become a problem for me when I get it.