@Shewolf13 , kind of makes me think that moving all their items etc isn't worth the effort then, especially if its a bug. I did think it was quite strange how all of a sudden it started. It happens with emotions all the time in my dynasty game. Every single time they change emotion I have to hit pause. And they change emotions a lot!
Well... decision made, I'll still move everything and transfer funds over into the retail lot and see what happens. I guess if it's a bug then game play will still be painful and if it solves some/all issues then we'll know. (Maybe.)
*Edited: Well, I transferred $9,000,000 over and headed back to the home lot and sold a lot of items that were just cluttering up the place. Everything ran really smoothly for about half an hour real life time and then the head bobbing started again. Not nearly so badly though, as so far (touch wood) I haven't had to hit pause. I can cope with the slight delay/head bob thing as long as it sorts itself out so for now just buying the retail lot and transferring the simoleons across was enough to improve game play.