I added my profile to a friend's ps3 and I gained some trophies for Uncharted 2, but after syncing the trophies, and then going back to my own system the trophies I recenently gained under my profile on my friends system are not there. It's like it never happened. Can trophies not be synced properly from the same profile on multiple systems?
Sometimes the sync does not confirm and instead of saying properly synced it will say not sycned. Also make sure you are checking the psn accounts trophies. for when you check the user account on the ps3 the trophies will only show the ones you had gotten on your ps3.