grouping vs detailed, still very problematic

I posted this question quite some time ago, but unfortunately, the problem persists:
http://www.experts-exchange.com/Microsoft/Development/MS-SQL-Server/Q_23472149.html

Very long story short, this report is done on a certain type of trade, called an 'strade'.  The 1st query is a detailed report of all strades.  The 2nd query is a summation of the detailed report.  For example, if 1st report includes 50 trades for userA, 10 of which were 'strades', then the summation will be the volume of the 50 totaltrades, along with the volume and count of the 10 strades.  

It has come to my attention that some of them are correct, others are reported inaccurately.  For example, this one is coming back as 16 strades, when it should be 7.  

First query returns 7 records:
SELECT DISTINCT b.EndPoint,b.UserID AS BUserID,b.AcctID AS BAcctID,s.UserID AS SUserID,s.AcctID AS SAcctID,b.Symbol,b.Quantity, b.Price,
CONVERT(VARCHAR(10),b.timefield,101)+' '+SUBSTRING(CONVERT(VARCHAR(20),b.timefield,100),13,7) AS TradeTime
FROM database.dbo.strades b WITH (NOLOCK)
INNER JOIN database.dbo.strades s WITH (NOLOCK)
  ON b.endpoint = s.endpoint
  AND b.Quantity = s.Quantity
  AND b.Price = s.Price
  AND b.tradetime = s.tradetime
  AND b.side = 'B'
  AND s.side = 'S'
AND b.endpoint = 'cccc' and b.Userid = 'abc' and b.symbol = 'ymu8'
ORDER BY EndPoint,BUserID,b.Symbol

endpoint   buserid       bacctid    suserid         sacctid    s.symbol   s.qty   s.price, s.time
cccc    abc     0814    CH      08139      YMU8      1   12169.00000000      06/17/2008  2:24PM
cccc    abc      08142    JR      08139      YMU8      1   12167.00000000      06/17/2008  2:39PM
cccc   abc      08142   JR      08139      YMU8      1   12169.00000000      06/17/2008  2:21PM
cccc  abc      08142   JR      08139      YMU8      1   12195.00000000      06/17/2008 11:33AM
cccc  abc      08142   JR      08139      YMU8      1   12213.00000000      06/17/2008 12:24PM
cccc   abc      08142   JR      08139      YMU8      1    12221.00000000      06/17/2008 10:29AM
cccc   abc      08142   JR      08139      YMU8      1   12255.00000000      06/17/2008  9:34AM

Second one does a summation on the results of the first, yet it gives a total count of 16, instead of the 7 identified in query #1 :

SELECT b.endpoint,b.userID,b.Symbol,SUM(b.quantity)AS STradeVol,COUNT(*) AS TotalSTrades
  FROM database.dbo.strades b WITH (NOLOCK)
   INNER JOIN database.dbo.strades s WITH (NOLOCK)
        ON b.endpoint = s.endpoint
      AND b.Quantity = s.Quantity
        AND b.Price = s.Price
        AND b.tradetime = s.tradetime
        AND b.side = 'B'
      AND s.side = 'S'
AND b.endpoint = 'cccc' aND b.userID = 'abc' and b.symbol = 'YMU8'
     GROUP BY b.endpoint,b.userID,b.Symbol

endpoint     userid         symbol        stradeVolume         totalSTrades
cccc           abc             YMU8      16      16      

Why do these two queries produce different resultsets?    The first details 7 records, the count in the summation should be 7, not 16.Start Free Trial