http://bugs.winehq.org/show_bug.cgi?id=58468
--- Comment #5 from koehler@dtv-verkehrsconsult.de --- Starting isql with command line option -m2 (merge diagnostic) gives a little more details on the failure when creating a new database.
It says: 0144:fixme:netapi32:NetWkstaUserGetInfo Level 1 processing is partially implemented 0144:err:winediag:ntlm_fork Can't start ntlm_auth (Datei oder Verzeichnis nicht gefunden). Usually you can find it in the winbind package of your distribution. 0144:fixme:process:CreateBoundaryDescriptorA "FirebirdCommonBoundary", 0 - stub Statement failed, SQLSTATE = HY000 Wrong file for memory mapping, see details in firebird.log