changes in sqlite.db structure from 0.2.1 to 0.3?

[Zingaro2002]

Hi guys!
2 days ago I've upgraded my roundcube installation (with a package on Ispconfig 2.2.33 on ubuntu 8.04) from 0.2.1 to 0.3 stable.
Before upgrading I backuped up my sqlite.db file and then, at the end, I recovered it and overwritten above the new one.
Everything seems to work fine: I had back my address book, my signature and my preferences.
I'de like to know: has sqlite.db file changed (I mean: the db structure) from RC 0.2.1 stable to RC 0.3 stable?
If yes, what are changes?
What might be possible problems if I keep the old one?

Thanks