I just did a complete re-install last night. I remember when I uninstalled World Adventures, I got a message that something about what would happen if I had a game where my Sim is in a foreign country. I don't recall what it said, but I'm thinking that maybe that's the problem with your game. Maybe if you're in a foreign country when you uninstall WA, it will revert to the beginning of a new game. What you need is a save that's pre-travel.