PHP errors using Nucleus importer

Hi all.

I have finally decided to change my CMS to WordPress.
My ancient CMS was Nucleus 3.15. I’ve happily find a converter script, but it doesn’t work for me, at it prints in the screen some ‘weird’ (at least for me), php errors.
Here they are:

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /home/algarine/public_html/misosofos/wordpress/nucleus/in_step_2.php on line 162

converting nucleus entries:
error getting nucleus blogs.
Unknown column ‘iurltitle’ in ‘field list’

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /home/algarine/public_html/misosofos/wordpress/nucleus/in_step_2.php on line 174

It could be my fault, because I set all wp prefixes to wp2? (Because I wanted to import them to my second blog.)

Thanks you in advantage, and sorry for my bad English.