I don't think you needed to worry, but put that aside for the moment.
This is a new one on me. I searched and found KB04461-Unable to restore read only databases when using the Advanced Backup and Restore function of BlackBerry Desktop Manager
. Take a look at that and see if it helps. I don't know how it applies to password keeper, but, hey, it's worth trying.
EDIT: I just noticed that article referrs to BES. Maybe it's doesn't apply to your problem?
EDIT #2: I'm in over my head. Searching on that error message, everyting I find is referrencing BES. If you are on BES, then see that link I posted. If you are, then maybe the links will help.