MySQL indexes stop working - php

Question

I am working on News website, the table (news) contain about 200,000 rows.
I use Zend framework 1.
the website was working very good, but from a week ago, I have found some errors in data retrieve from the queries.
I use zend paginator, like this:
$paginator = Zend_Paginator::factory($select);
$paginator->setItemCountPerPage(10);
$pageCounter = $paginator->count();
so $pageCounter return 0,
when I try to debug the error, I have tried to drop the indexes from the database table and create the index again, then the problem was resolved the website back to work again.
but every couple days this problem back again.
the tables I use is:
CREATE TABLE `news` (
`news_id` int(11) NOT NULL AUTO_INCREMENT,
`category_id` int(11) DEFAULT NULL,
`news_type` enum('text','photo','video') DEFAULT 'text',
`news_title` varchar(255) NOT NULL,
`news_url` varchar(255) NOT NULL,
`news_date` datetime NOT NULL,
`news_image` varchar(255) DEFAULT NULL,
`video` varchar(255) DEFAULT NULL,
`news_source` int(11) NOT NULL DEFAULT '0',
`author_id` int(11) NOT NULL DEFAULT '0',
`news_brief` text,
`news_content` mediumtext,
`meta_title` varchar(255) NOT NULL,
`meta_description` varchar(255) DEFAULT NULL,
`meta_keywords` varchar(255) DEFAULT NULL,
`status` tinyint(2) NOT NULL DEFAULT '1',
`news_read` int(11) DEFAULT '0',
`old_id` int(11) DEFAULT NULL,
`old_section_id` int(11) DEFAULT NULL,
`old_section` varchar(50) DEFAULT NULL,
`lang` varchar(10) DEFAULT NULL,
`featured` int(11) NOT NULL DEFAULT '0',
`in_timeline` tinyint(2) NOT NULL DEFAULT '0',
`is_highlight` tinyint(2) NOT NULL DEFAULT '0',
`home_exclusive` tinyint(2) NOT NULL DEFAULT '0',
`home_articles` tinyint(4) NOT NULL DEFAULT '0',
`home_articles_selected` tinyint(4) NOT NULL DEFAULT '0',
`home_mostread` tinyint(4) NOT NULL DEFAULT '0',
`video_featured` tinyint(4) NOT NULL DEFAULT '0',
`photos_featured` tinyint(4) NOT NULL DEFAULT '0',
`party_featured` tinyint(4) NOT NULL DEFAULT '0',
`party_activity` tinyint(4) NOT NULL DEFAULT '0',
`sport_featured` tinyint(4) NOT NULL DEFAULT '0',
`fnoun_featured` tinyint(4) NOT NULL DEFAULT '0',
`special_reports` tinyint(4) NOT NULL DEFAULT '0',
`mainnav` tinyint(4) NOT NULL DEFAULT '0',
PRIMARY KEY (`news_id`),
KEY `News_Category_idx` (`category_id`),
KEY `News_Type` (`news_type`),
KEY `News_Date` (`news_date`),
KEY `News_Read` (`news_read`),
KEY `old_id` (`old_id`),
KEY `Sources` (`news_source`),
KEY `Authors` (`author_id`),
KEY `Featured` (`featured`),
KEY `Articles` (`home_articles`),
KEY `Mostread` (`home_mostread`),
KEY `video_featured` (`video_featured`,`photos_featured`),
KEY `party_activity` (`party_activity`),
KEY `sport_featured` (`sport_featured`,`fnoun_featured`),
KEY `old_section_id` (`old_section_id`),
KEY `old_section` (`old_section`),
KEY `old section id` (`old_section_id`),
KEY `old section` (`old_section`),
KEY `articles_selected` (`home_articles_selected`),
KEY `URL` (`news_url`),
KEY `special_reports` (`special_reports`),
KEY `mainnav` (`mainnav`),
KEY `status` (`status`),
KEY `in_timeline` (`in_timeline`),
KEY `is_highlight` (`is_highlight`),
KEY `home_exclusive` (`home_exclusive`),
KEY `party_featured` (`party_featured`),
FULLTEXT KEY `news_title` (`news_title`)
) ENGINE=InnoDB AUTO_INCREMENT=167614 DEFAULT CHARSET=utf8
the columns (status - featured - in_timeline - is_highlight) type was (ENUM) but I have changed to (tinyint)
It works for a few days, but the problem come back again.
so I have to drop the indexed and create it again.
I don't know what is the problem?
can anyone help, please.
The Explain Query, it's the same when the problem happen and after I drop the indexes and create it again.
SQL query: Explain SELECT `N`.`news_id`, `N`.`news_title`, `N`.`news_url`, `N`.`news_image`, `N`.`news_type`, `N`.`news_date`, `N`.`is_highlight`, `N`.`news_brief`, `C`.`category_name`, `C`.`category_url`, `C`.`category_color`, `NT`.*, GROUP_CONCAT(T.tag_name separator ",") AS tags, GROUP_CONCAT(T.tag_url separator ",") AS `tags_urls` FROM `news` AS `N` INNER JOIN `news_categories` AS `C` ON C.category_id = N.category_id AND C.status = "1" LEFT JOIN `news_tags_relation` AS `NT` ON NT.news_id = N.news_id LEFT JOIN `news_tags` AS `T` ON T.tag_id = NT.tag_id WHERE (N.status = "1" AND N.category_id = "22") GROUP BY `N`.`news_id` ORDER BY `N`.`news_date` DESC;
Rows: 4
This table does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available.
the table in the attached images