Subject RE: [firebird-support] Can a user change his own password?
Author Sasha Matijasic
> With Firebird 2.1.0 it worked OK.
> What's going wrong here?

If I'm not mistaken everything is as it should be. The ability for non sysdba users to change passwords was added in 2.0. Check the release notes.
I never worked in production with 1.5 series but I think it's possible to modify security database, you get get more details on Ivan Prenosil's site