Reporting Services :: Unable To Calculate Running Balance Column Correctly In SSRS

I created a view that i want to use in ssrs.In the view there is a column for running balance.In the table contain transaction of inventory with their quantity.

"SELECT     TOP (100) PERCENT ITEMNMBR, TRXSORCE, DOCTYPE, DOCNUMBR, DOCDATE, HSTMODUL, UOFM, UNITCOST, EXTDCOST, TRXQtyInBase,
                          (SELECT     SUM(TRXQtyInBase) AS Expr1
                            FROM          dbo.INVTRXB AS b
                            WHERE      (DEX_ROW_ID <= a.DEX_ROW_ID) AND (ITEMNMBR = a.ITEMNMBR)) AS ENDQTY
FROM         dbo.INVTRXB AS a
ORDER BY ITEMNMBR, DOCDATE"

If i run the query on sql or use the view on ssr. The end qty is  not showing accurately.I ran it on another database it works perfectly. Then i noticed that the dex_row_ID of the second database is sequential as the date. But for the initial database it was not sequential as with the date.