It creates pagebar on lists (for ex. on category or search results) and Next Post & Previous Post links on each post.
Zamango Page Navigation uses few features which were implemented in WordPress v.2.8.0 so it will not work correctly on older versions. Althought I use it myself on wordpress 2.7.4 with few limitaions.
Just uncheck both "before post" & "after post" checkboxes on a
Quick links on single post tab of plugin options page.
To make native theme navigation bar absolutely invisible just add following string into plugin's CSS (without apostrophes):
It must help in most themes. If not then it's needed to edit your theme files (but do it on your own responsibility).