Clarification needed, to aid in troubleshooting this issue:
1. Is this game lag experienced only in OL, only in the "home world," or in both OL and the "home world"? Which world did it happen in, first?
2. Have you checked for routing errors in the world? Stuck sims? Stuck animals in home world? Multiplying spawners? Abandoned cars/vehicles? Too many NPCs spawning at certain places in the world? Any other causes for lag noted in any of Crinrict's stickied threads? (It is important to eliminate all known causes for lag, before we can accurately pinpoint a new cause for lag never seen before ITF.)
3. Is this happening in factory reset games or is it only in pre-played saves from earlier expansions?
4. Are you playing with any EA cheats turned on?
5. Did you visit Utopia? Did you visit Dystopia?
6. Is the same approximate amount of time needed for causing the corruption/lag similar in every game played, or does the amount of time needed to cause the corruption/lag directly relate to the number of time jumps? In other words, can you "cause" the problem by doing several consecutive time jumps, with only one day or night between jumps?
7. Are you spending most of your play time in the "home world" or in OL?
8. Can you move the lagging save to a factory reset game, and still experience the lag? (This would eliminate lag caused by anything other than the save, itself.)
9. Please let us know your computer specs, which OS, and etc -- all the things Crinrict asks in her bug thread.
I think those of you with this problem should do some strong testing until you can get repeatable data. A real bug or real routing issues in a world can, with a great deal of sleuthing, be repeated reliably. Otherwise, since it takes so long to get results, something like this may never be found.
I played my first test game (factory reset for ITF, no mods, no CC - not even store stuff) for somewhere between 40-45 sim days, and went back and forth between MF and OL over a dozen times during that time period, but spent most of my play time in OL. My game was still playing perfectly, with no lag. I did visit Utopia for a short while, but did not ever visit Dystopia. I tested practically every new feature in the ITF. The only repeatable bugs I found were the ones I listed in Crinrict's bug thread.
Since I have now moved on to a different world, where I am testing the longevity of mermaids in LL/OL with only a swimming pool that has a saltwater designator placed in it (by using the cheat console) available to alleviate her need for ocean water, I won't be much help in testing the kind of bug you are talking about in this thread.