Sí la linea exacta es:
Código PHP:
<?php do_action('register_form'); ?>
Dentro del "trozo":
Código PHP:
<?php do_action('register_form'); ?>
<p id="reg_passmail"><?php _e('A password will be e-mailed to you.') ?></p>
<br class="clear" />
<input type="hidden" name="redirect_to" value="<?php echo esc_attr( $redirect_to ); ?>" />
<p class="submit"><input type="submit" name="wp-submit" id="wp-submit" class="button-primary" value="<?php esc_attr_e('Register'); ?>" tabindex="100" /></p>
</form>
<p id="nav">
Gracias por contestar!