> Since installing the latest 2.5 release candidate, I always get "Unexpected output buffer value" error when I try to add a user.
> It doesn't matter what tool I use, Flamerobin, IBExpert, the message is the same. I tried to install on Windows 2003 server,
> Windows XP en Fedora Linux 12. On all 3 operating systems the same error. The windows install was SuperClassic mode.
>
> Any ideas ?

Try GSEC, or FSQL (http://www.volny.cz/iprenosil/interbase/fsql.htm)

CONNECT SERVICE 'localhost' USER SYSDBA PASSWORD 'masterkey';
SVC_MGR CREATE USER 'ABC' PASSWORD 'abc';
SVC_MGR SHOW USER;