Twenty Ten theme Category full text

edit loop.php;

change this:

<?php if ( is_archive() || is_search() ) : // Display excerpts for archives and search. ?>

to this:

<?php if ( is_search() ) : // Display excerpts for  search. ?>

this occurs twice – change at least the occurence nearer to the end of the file.

probably with a plugin, http://wordpress.org/extend/plugins/tags/pagination