OK, it’s happened to me now too!
I added a few more albums to the Lacie but they never appeared when I connected iTunes to it. I rebuilt the database, enabled/disabled the media server – tried everything. I can see and play the mp3 files directly but they are simply not added to the database.
Hmm. Rolling back may be my only option?
Don’t suppose you heard back from Lacie did you raphaeld?