My sims recently went to China. I bought the martial arts training dummy, the fortune cookie machine, and something else that I can't remember off the top of my head right now. When she got back from her trip, none of those items were in her inventory, at all!!
When her roomie got back, he had no wishes. I had fulfilled all of his right before the trip was over. When they got back, nada! It took about 4 or 5 hrs to even get ONE!!