I've got a house in Pleasantview that is now unplayable (unlit plumbob overhead in n'hood view) because the game is convinced the family is still on vacation. Only half the household went on vacation, they got stuck via the taxi-takes-them-right-back-on-vacation-after-bringing-them-home glitch (with the taxi refusing to show back up at the vacation property after they made the call to return home), and I ended up teleporting them into another lot in Pleasantview, and moving them in, as Kat suggested. The vacation house (Brickstone Chateau in Twikkii Island) is now uninhabited, but the original Pleasantview house is still unplayable, even though there are about 5 sims living in that house that never even went on the vacation. I had the owner of the vacation lot sell the property (he was one of the stuck sims), but that didn't free the Pleasantview lot, either.
I do not have the patch installed because...I don't know, at this point. How much more problematic can things get?