Addera flertal tabeller, ta bort NULL

Hallojse,
tillbaka för lite vägledning.

Fick tipset att ifall ett värde returnerar NULL så kan man använda coalesce för att typa andra värden som skall användas. t.ex.
coalesce(list0,0)

Detta är ju super. Men jag försöker nu ta bort resultat ifall ett värde inte existerar. Det funkar toppen ifall jag väljer någon av list variablerna t.ex. WHERE list0 > 0 i slutet men ifall jag använder totalScore så funkar det inte alls, WHY? :q

Såhär ser frågan ut.

SELECT playerId, scoreName, scoreDate, list0, list1, list2, list3, list4, list0 +list1 +list2 +list3 +list4 AS totalScore 
FROM (SELECT h1.playerId,
		h1.scoreName, 
		h1.scoreDate, 
			(SELECT MIN(scoreTime) 
				FROM tbl_highscores 
				WHERE scoreListId = 0  
				AND playerId = h1.playerId
				AND projectId = 1) AS list0 , 
			(SELECT MIN(scoreTime)  
				FROM tbl_highscores 
				WHERE scoreListId = 1
				AND playerId = h1.playerId
				AND projectId = 1) AS list1 , 
			(SELECT MIN(scoreTime) 
				FROM tbl_highscores 
				WHERE scoreListId = 2
				AND playerId = h1.playerId
				AND projectId = 1) AS list2 , 
			(SELECT MIN(scoreTime) 
				FROM tbl_highscores 
				WHERE scoreListId = 3 
				AND playerId = h1.playerId
				AND projectId = 1) AS list3 , 
			(SELECT MIN(scoreTime) 
				FROM tbl_highscores 
				WHERE scoreListId = 4 
				AND playerId = h1.playerId
				AND projectId = 1) AS list4  
		FROM tbl_highscores h1 
		GROUP BY h1.playerId 
		ORDER BY scoreDate ASC) dt 
	WHERE totalScore > 0 [B]<---- HÄR BLIR DET FEL!!![/B]
	ORDER BY totalScore ASC
	LIMIT 0,10;