Someone else reported that "Continue Reading" appears even though the "more" text can be set in the widget, but I can't reproduce this. In my tests, "more..." appears in the widget, as it should, and "Continue Reading" appears in the body of the post -- not in the sidebar -- which means it's generated by the_content() and has nothing to do with my plugin.
Look in the Twenty Ten loop.php file. You'll see this:
<?php the_content( __( 'Continue reading <span class="meta-nav">→</span>', 'twentyten' ) ); ?>
You can change the text directly by editing the file, or you can work with the translation files for the Twenty Ten theme.