Have I done something wrong when adding my media? Recently I recreated my database from scratch (deleted mm.db, I accidentally corrupted it or something) I added all my media in and I have noticed that quite a few of my songs are much longer than they should be (7 minutes instead of 3.5 etc). My movies have also done similar things.

Can I rescan these files for the correct time values? Or do I have to recreate mm.db again? It may also be possible some of my songs have been cut short too, though I am yet to confirm this.
Cheers,
Ryan.