It's complicated

Well, I'm not a guru when it comes to programming - just have a half year drupal experience (not counting the more simple systems), creative thinking and about a hundred installed modules on my website. But, I don't think that Default Node Gallery is the most complex of them. Nevertheless I was not able to install this module on working site. Now I've installed fresh D6 site with minimum modules especially for testing DNG. But result is the same. It's not working at all (I always get a standart NG installation, regardless of whether installed DNG or not). Every time at user login (with DNG installed) I see following warning.

user warning: Table 'gb_node_gallery_relationships' doesn't exist query: SELECT * FROM node_gallery_relationships WHERE rid NOT IN (SELECT rid FROM node_gallery_default WHERE uid = 3) in /home/virtwww/.../http/sites/all/modules/node_gallery_default/node_gallery_default.module on line 137.

Maybe installation procedure is a bit more complicated than described in the manual? Maybe there needed detailed step by step instruction? Thank you very much.