Having seen 2 different accounts in use in the same space at the same time, what one person sees on their screen is not always exactly the same as what another person sees. You may see your avatar facing one way, the other account may see the avatar facing another way. I had also noticed before that I might go to the park, a friend may be in the park, but we don't see each other, if there is more than one park maybe, or some other management system used, to avoid the park becoming overcrowded. Another thing that happened was in the lockwood xp and I managed to get the starfish, it was at the edge of thespace, but my friend said they could not get it to respond(give xp). & finally the validating purchases, in my experience, the more I buy the longer I wait.... not a hard and fast rule, it has been rather sporadic, say I bought the luxury train apartment I waited a good while for that, close to 15 minutes iirc, but it seems for other people it's just a general wait a particular length of time. They're all subtle differences, but it is good to bear it in mind.