Problem viewing trophies in PSN?

Hey can somebody please help me with this one?? I seem to have some problem syncing some of my PS3 games with the PSN, I can view my trophies fine on my PS3, but when I log to the Playstation website to view them it doesn't show me all the games, but it does show me the total number of trophies that I have earned. So why does that happens?