opheliana ... the ojaccess.db file is created for you by the auth.pl script after you create your first login. It sounds as though the file can't be created, which in turn sounds as though you need to check the permissions on the /ojauth directory in your cgi-bin. Make sure that one is set to at least 755 (rwxr-xr-x) ... while you're there, also check the permissions on the /ojtemplates directory and then the directory for the index files etc (in my case it's /openjournal and /openjournal/story). Good luck.

Oh and re the ojaccess.db file: if you ever forget a password or something, you can FTP in and edit that file or delete it and start afresh. I don't know what that would do to any existing journal files, so be sure to back them up first.