Summer Time Timezone and Timestamps comparison

DROP DATABASE IF EXISTS test ;

CREATE DATABASE test DEFAULT CHARSET=utf8 ;

USE test ;

SET @@session.time_zone = 'SYSTEM' ;

SET @OLD_TIME_ZONE=@@TIME_ZONE ;

SET TIME_ZONE='+00:00' ;

CREATE TABLE `tab` (

  `Name` varchar(16) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,

  `Timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,

  UNIQUE KEY `Name` (`Name`,`Timestamp`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `tab` VALUES 

	('n1','2014-10-25 21:11:11'),

	('n2','2014-12-22 21:22:22');

SET TIME_ZONE=@OLD_TIME_ZONE ;

SELECT * FROM test.tab ;

# Returns 2 rows:

# +------+-----------------------+

# | Name |       Timestamp       |

# +------+-----------------------+

# |  n1  |  2014-10-26 01:11:11  |

# +------+-----------------------+

# |  n2  |  2014-12-23 00:22:22  |

# +------+-----------------------+

SELECT * FROM test.tab WHERE 

Name = 'n2' AND

Timestamp = '2014-12-23 00:22:22' ;

# Returns 1 row:

# +------+-----------------------+

# | Name |       Timestamp       |

# +------+-----------------------+

# |  n2  |  2014-12-23 00:22:22  |

# +------+-----------------------+

SELECT * FROM test.tab WHERE 

Name = 'n1' AND

Timestamp = '2014-10-26 01:11:11' ;

# Returns 0 rows!

# How so?