I istalled postnuke v061 with the first mentioned howto without any problems, here is what I did:
1. Create an e-bay (read-group, write-group) (local ftp-access without password) (cgi activated)
2. In the postnuke archive there is a dump-file for the database wich comes with postnuke. I installed it with dump. (the creation of a database, as in the mentioned howto didnt work for me, might be my fault.
3. Copy the files from the postnuke archive into the html directory of the i-bay.
4. Set all the directories to 777 and all the files to 666. (If it works, you should set the configuration-php-file and the admin.php to 600 for better security.
5. In the config-file you need some informations about your database. (password from /root/my.conf etc)
6. Run the installation and the admin.php
Thats all I did.
Line 141 in my mainfile.php sets the query language. Cant imagine, that this is your problem because I have no settings here for the query-language. Might be, you tried to make some changes.
Karl W. Mueller