These newer and older posts links are from your theme and cannot be removed by the plugin. But you can remove them yourself. For example if you use the twenty eleven theme and you want to remove these links from the categories overview then you edit category.php and remove the following lines:
<?php twentyeleven_content_nav( 'nav-above' ); ?>
<?php twentyeleven_content_nav( 'nav-below' ); ?>
The text links for older and newer entries are not from the plugin but from your theme, you should do translations there. THe plugin only adds the pagenumbers and we cannot really translate those:)
I have tried on the twenty eleven theme on different websites to test it and it works everytime. Please try on a fresh install or try deactivating other plugins to find out if there is some conflict maybe.
