Index: src/wp-includes/wp-db.php
===================================================================
--- src/wp-includes/wp-db.php	(revision 32260)
+++ src/wp-includes/wp-db.php	(working copy)
@@ -2462,8 +2462,19 @@
 		$mb_charsets = array(
 			'ascii'   => 'ASCII',
 			'big5'    => 'BIG-5',
+			'cp1251'  => 'Windows-1251',
+			'cp866'   => 'CP866',
+			'cp932'   => 'CP932',
 			'eucjpms' => 'eucJP-win',
+			'euckr'   => 'EUC-KR',
 			'gb2312'  => 'EUC-CN',
+			'greek'   => 'ISO-8859-7',
+			'hebrew'  => 'ISO-8859-2',
+			'koi8r'   => 'KOI8-R',
+			'latin2'  => 'ISO-8859-2',
+			'latin5'  => 'ISO-8859-9',
+			'latin7'  => 'ISO-8859-13',
+			'sjis'    => 'SJIS',
 			'ujis'    => 'EUC-JP',
 			'utf32'   => 'UTF-32',
 		);
@@ -2534,7 +2545,7 @@
 
 		if ( $db_check_string ) {
 			$queries = array();
-			foreach ( $data as $col => $value ) {
+			foreach ( $data as $col => &$value ) {
 				if ( ! empty( $value['db'] ) ) {
 					if ( ! isset( $queries[ $value['charset'] ] ) ) {
 						$queries[ $value['charset'] ] = array();
@@ -2542,6 +2553,7 @@
 
 					// Split the CONVERT() calls by charset, so we can make sure the connection is right
 					$queries[ $value['charset'] ][ $col ] = $this->prepare( "CONVERT( %s USING {$value['charset']} )", $value['value'] );
+					unset( $value['db'] );
 				}
 			}
 
Index: tests/phpunit/tests/db/charset.php
===================================================================
--- tests/phpunit/tests/db/charset.php	(revision 32260)
+++ tests/phpunit/tests/db/charset.php	(working copy)
@@ -55,19 +55,25 @@
 				'expected' => "H€llo\xf0\x9f\x98\x88World¢"
 			),
 			'koi8r' => array(
-				// koi8r is a character set that needs to be checked in MySQL
 				'charset'  => 'koi8r',
 				'value'    => "\xfdord\xf2ress",
 				'expected' => "\xfdord\xf2ress",
-				'db'       => true
 			),
 			'hebrew' => array(
-				// hebrew needs to be checked in MySQL, too
 				'charset'  => 'hebrew',
 				'value'    => "\xf9ord\xf7ress",
 				'expected' => "\xf9ord\xf7ress",
-				'db'       => true
 			),
+			'cp1251' => array(
+				'charset'  => 'cp1251',
+				'value'    => "\xd8ord\xd0ress",
+				'expected' => "\xd8ord\xd0ress",
+			),
+			'tis620' => array(
+				'charset'  => 'tis620',
+				'value'    => "\xccord\xe3ress",
+				'expected' => "\xccord\xe3ress",
+			),
 			'false' => array(
 				// false is a column with no character set (ie, a number column)
 				'charset'  => false,