Objects and furniture disappearing and moving

I have most of the expansion and stuff packs, and have been playing with no big problems. I installed seasons, and everything was working fine. Then all of a sudden my furniture started disappearing from the houses or moving to odd spots. For instance, the fireplace moves to the middle of the living room. Has anyone had this problem or know how to fix this? The furniture that disappears, is actually gone. There is nothing in its spot and I have to put new furniture everytime. It happens when I start playing from having the game paused.