1bitor2 on "[Plugin: WordPress SEO by Yoast] SEO is vital, why trust to any breakable plugin ??"

Strip /category/ in permalink:
Copy this plugin into your function.php. Install it by extension panel, but don't enable it. As this, you could be warmed of update.
There are many other ways to do this, feel free to search on web to find the one wich feet your needs.
This one work out of the box for me.

/*
 Plugin Name: WP No Category Base
 Plugin URI: http://blinger.org/wordpress-plugins/no-category-base/
 Description: Removes '/category' from your category permalinks.
 Version: 1.1.1
 Author: iDope
 Author URI: http://efextra.com/
 */

/*  Copyright 2008  Saurabh Gupta  (email : saurabh0@gmail.com)

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

// Refresh rules on activation/deactivation/category changes
register_activation_hook(__FILE__, 'no_category_base_refresh_rules');
add_action('created_category', 'no_category_base_refresh_rules');
add_action('edited_category', 'no_category_base_refresh_rules');
add_action('delete_category', 'no_category_base_refresh_rules');
function no_category_base_refresh_rules() {
	global $wp_rewrite;
	$wp_rewrite -> flush_rules();
}

register_deactivation_hook(__FILE__, 'no_category_base_deactivate');
function no_category_base_deactivate() {
	remove_filter('category_rewrite_rules', 'no_category_base_rewrite_rules');
	// We don't want to insert our custom rules again
	no_category_base_refresh_rules();
}

// Remove category base
add_action('init', 'no_category_base_permastruct');
function no_category_base_permastruct() {
	global $wp_rewrite, $wp_version;
	if (version_compare($wp_version, '3.4', '<')) {
		// For pre-3.4 support
		$wp_rewrite -> extra_permastructs['category'][0] = '%category%';
	} else {
		$wp_rewrite -> extra_permastructs['category']['struct'] = '%category%';
	}
}

// Add our custom category rewrite rules
add_filter('category_rewrite_rules', 'no_category_base_rewrite_rules');
function no_category_base_rewrite_rules($category_rewrite) {
	//var_dump($category_rewrite); // For Debugging

	$category_rewrite = array();
	$categories = get_categories(array('hide_empty' => false));
	foreach ($categories as $category) {
		$category_nicename = $category -> slug;
		if ($category -> parent == $category -> cat_ID)// recursive recursion
			$category -> parent = 0;
		elseif ($category -> parent != 0)
			$category_nicename = get_category_parents($category -> parent, false, '/', true) . $category_nicename;
		$category_rewrite['(' . $category_nicename . ')/(?:feed/)?(feed|rdf|rss|rss2|atom)/?$'] = 'index.php?category_name=$matches[1]&feed=$matches[2]';
		$category_rewrite['(' . $category_nicename . ')/page/?([0-9]{1,})/?$'] = 'index.php?category_name=$matches[1]&paged=$matches[2]';
		$category_rewrite['(' . $category_nicename . ')/?$'] = 'index.php?category_name=$matches[1]';
	}
	// Redirect support from Old Category Base
	global $wp_rewrite;
	$old_category_base = get_option('category_base') ? get_option('category_base') : 'category';
	$old_category_base = trim($old_category_base, '/');
	$category_rewrite[$old_category_base . '/(.*)$'] = 'index.php?category_redirect=$matches[1]';

	//var_dump($category_rewrite); // For Debugging
	return $category_rewrite;
}

// For Debugging
//add_filter('rewrite_rules_array', 'no_category_base_rewrite_rules_array');
//function no_category_base_rewrite_rules_array($category_rewrite) {
//	var_dump($category_rewrite); // For Debugging
//}

// Add 'category_redirect' query variable
add_filter('query_vars', 'no_category_base_query_vars');
function no_category_base_query_vars($public_query_vars) {
	$public_query_vars[] = 'category_redirect';
	return $public_query_vars;
}

// Redirect if 'category_redirect' is set
add_filter('request', 'no_category_base_request');
function no_category_base_request($query_vars) {
	//print_r($query_vars); // For Debugging
	if (isset($query_vars['category_redirect'])) {
		$catlink = trailingslashit(get_option('home')) . user_trailingslashit($query_vars['category_redirect'], 'category');
		status_header(301);
		header("Location: $catlink");
		exit();
	}
	return $query_vars;
}