Are you seeing double?

SELECT * FROM gallery2 WHERE topic_id="398678" UNION SELECT * FROM gallery2 WHERE topic_id="436390" UNION SELECT * FROM gallery2 WHERE topic_id="1637727" UNION SELECT * FROM gallery2 WHERE topic_id="391029" UNION SELECT * FROM gallery2 WHERE topic_id="1745741" UNION SELECT * FROM gallery2 WHERE topic_id="200137" UNION SELECT * FROM gallery2 WHERE topic_id="1027503" UNION SELECT * FROM gallery2 WHERE topic_id="4052" UNION SELECT * FROM gallery2 WHERE topic_id="672186" UNION SELECT * FROM gallery2 WHERE topic_id="781026" UNION SELECT * FROM gallery2 WHERE topic_id="396692" UNION SELECT * FROM gallery2 WHERE topic_id="22040" UNION SELECT * FROM gallery2 WHERE topic_id="1279761" UNION SELECT * FROM gallery2 WHERE topic_id="1724000" UNION SELECT * FROM gallery2 WHERE topic_id="726680" UNION SELECT * FROM gallery2 WHERE topic_id="216596"