Problem med SQL-sats

Har den här koden som funkar utmärkt:

Select Sum(My_Tips_Score) As poang, 
User_Firstname, User_Lastname, Community_Name
 From My_Tips Inner Join Users On User_ID=My_Tips_Owner 
Inner Join Community On My_Tips_Community=Community_ID 
Inner Join Matcher On Match_ID=My_Tips_MatchID 
Where Match_Score_1>'' And Match_Score_2>''  
Group By Community_Name, User_ID Order By 1 Desc Limit 50

Men nu vill jag bara ha dom senaste 30 matcherna:

Select Sum(My_Tips_Score) As poang, 
User_Firstname, User_Lastname, Community_Name
 From My_Tips Inner Join Users On User_ID=My_Tips_Owner 
Inner Join Community On My_Tips_Community=Community_ID 
Inner Join Matcher On Match_ID=My_Tips_MatchID 
Where (Match_Score_1>'' And Match_Score_2>'' 
Order By Match_Tid Desc Limit 30) 
Group By Community_Name, User_ID Order By 1 Desc Limit 50

tänkte jag men icke!

Nån som har ett förslag?