If you’ve upgraded your PS3 hard disk since the 2.40 Trophy firmware update, you might be shocked to see that even after a full backup and restore of your disk contents, your beloved Trophies are gone!
But don’t despair, you don’t need to play all those games again. The Trophies are still stored in your online PSN profile. But you need to trigger a trophy synchronisation, by winning a new Trophy that you don’t yet have, and then the next time you check your Trophy list in the XMB, following the synchronisation, all your hard won Trophies are restored. Phew!