Sims 3 hangs on vacation end? [SOLVED]

In my current save file, my sim has less than a day left on an 11-day trip to China. Problem is, the game hangs whenever I try to bring her back home, either by using the phone or by waiting for the day to end. Everything runs smoothly, I get the 12 hours/1 hour left messages normally, then it hangs just before the blue "time to go home" pop-up is supposed to appear.
To be clear, by "hang" I mean: Ambient movement (like fishes swimming in a pond) keeps going smoothly, but my sim's frozen in place and the game is unresponsive, though it can be alt-tabbed to and from easily and the rest of the system is fine. If left alone, the TS3W.exe process just sits in memory until killed, with its memory usage not moving at all.

The affected sim was created in a fairly messy game install (cobbled together from many sources over time, some modified installers, etc) that was in version 1.55 with all EPs and SPs up to Island Paradise. I did a clean reinstall of everything (from this site) just yesterday, going to v1.57 and adding Movie Stuff. I've had around 6 hours of play time between the reinstall and the problem arising. During that time, I've successfully sent that sim to France and brought her back.
I have very little CC (a few skintones and eyebrows, the store items, and NRaas MasterController/Overwatch/StoryProgression).

I've already tried the obvious - clear the caches, remove CC, resetsim - with no luck.
Any ideas?

Thanks for the suggestion - I ended up finding several ways to fix the situation. The Porter mod does work. 
For reference: after finding a backup of a save a few in-game days earlier and poking around a bit, it turns out that yup, the save is indeed corrupted. Whatever corrupts it happens at midnight going into day 11/11 of the vacation, no matter what I do in the couple of days before. Sending the sim home before then works fine, as does the metadata replacement method for recovering bad saves.

Helper Edit: Problem solved, topic closed.

-cat2006house