> It appears that you have created a role in your database privileges
> that has the name 'SYSDBA'. If so, then you have a big problem now,
> because you have disabled the *user* SYSDBA from accessing the database.
>
> Ordinary users will still be able to connect. However, you now have
> no user that can back up that database.

No problem. Backup can be done either by SYSDBA or by database owner.
If he has role SYSDBA, it means that database owner must be somebody else.
Simply connect with *any* user and look who the owner is.
Or look who is creator of SYSDBA role, then connect with that user and drop SYSDBA role.
Simple, isn't it ?

Ivan
http://www.volny.cz/iprenosil/interbase/