SQL2000 and SQL 2005 - Return Different Values from a SELECT statement

PMALLHD - Header View
 
SELECT     dbo.PM20000.VCHRNMBR, dbo.PM20000.DOCTYPE, dbo.PM20000.DOCNUMBR, dbo.PM20000.DOCAMNT, dbo.PM20000.PORDNMBR, 
                      dbo.PM20000.TRXSORCE, dbo.PM20000.TRXDSCRN, dbo.PM20000.VOIDED, dbo.PM20000.CURNCYID, dbo.PM20000.VENDORID, 
                      dbo.PM00200.VENDNAME
FROM         dbo.PM20000 INNER JOIN
                      dbo.PM00200 ON dbo.PM20000.VENDORID = dbo.PM00200.VENDORID
UNION ALL
SELECT     dbo.PM30200.VCHRNMBR, dbo.PM30200.DOCTYPE, dbo.PM30200.DOCNUMBR, dbo.PM30200.DOCAMNT, dbo.PM30200.PORDNMBR, 
                      dbo.PM30200.TRXSORCE, dbo.PM30200.TRXDSCRN, dbo.PM30200.VOIDED, dbo.PM30200.CURNCYID, dbo.PM30200.VENDORID, 
                      PM00200_1.VENDNAME
FROM         dbo.PM30200 INNER JOIN
                      dbo.PM00200 AS PM00200_1 ON dbo.PM30200.VENDORID = PM00200_1.VENDORID
 
PMALLGL - Lines View
 
SELECT     VCHRNMBR, DEBITAMT - CRDTAMNT AS AMOUNT, DSTINDX, DISTTYPE, VENDORID, TRXSORCE, PSTGDATE, PSTGSTUS
FROM         dbo.PM10100
UNION ALL
SELECT     VCHRNMBR, DEBITAMT - CRDTAMNT AS AMOUNT, DSTINDX, DISTTYPE, VENDORID, TRXSORCE, PSTGDATE, PSTGSTUS
FROM         dbo.PM30600
 
SQL - SELECT - STATEMENT THAT IS NOT WORKING
 
SELECT   PMALLGL.DISTTYPE,
   (CASE DISTTYPE
		WHEN 1 THEN 'CASH'
	    WHEN 2 THEN 'PAY'
		WHEN 3 THEN 'AVAIL'
		WHEN 4 THEN 'TAKEN'
        WHEN 5 THEN ' FNCHG' 
		WHEN 6 THEN 'PURCH'
		WHEN 7 THEN 'TRADE'
		WHEN 8 THEN 'MISC'
		WHEN 9 THEN 'FREIGHT'
		WHEN 10 THEN 'TAXES'
		WHEN 11 THEN 'WRITE'
		WHEN 12 then 'OTHER'
		WHEN 13 then 'GST'
		WHEN 14 then 'PPS'
		WHEN 15 then 'UNIT'
		WHEN 16 then 'ROUND'
		WHEN 17 then 'CURRENCY 1'
		WHEN 18 then 'CURRENCY 2'
		Else 'UNKNOWN'
      END)
        AS zDISTTYPE,
     (CASE DISTTYPE
		WHEN 1 THEN  'Cash Paid / Cash Out'
		WHEN 2 THEN  'Payables Control'
		WHEN 3 THEN  'Settlement Discount Available'
		WHEN 4 THEN  'Settlement Discount Taken'
		WHEN 5 THEN  'Finance Charges'
		WHEN 6 THEN  'Purchases GL Analysis'
		WHEN 7 THEN  'Trade Discount'
		WHEN 8 THEN  'Miscellaneous'
		WHEN 9 THEN  'Freight / Carriage'
		WHEN 10 THEN 'Taxes & VAT'
		WHEN 11 THEN  'Write Offs'
		WHEN 12 then  'Other Costs'
		WHEN 13 then  'GST'
		WHEN 14 then  'PPS'
		WHEN 15 then  'UNIT'
		WHEN 16 then  'Rounding'
		WHEN 17 then  'Currency Reval 1'
		WHEN 18 then  'Currency Reval 2'
		else  'UNKNOWN'
      END)
		AS DISTNAME,
        
		zAMOUNT = convert(money,(sum(PMALLGL.AMOUNT)))
 		 
 FROM { oj ((PMALLHD PMALLHD INNER JOIN PMALLGL PMALLGL ON PMALLHD.VCHRNMBR = PMALLGL.VCHRNMBR)  INNER JOIN GL00105 GL00105 ON PMALLGL.DSTINDX = GL00105.ACTINDX)  INNER JOIN GL00100 GL00100 ON GL00105.ACTINDX = GL00100.ACTINDX}
 
 WHERE PMALLHD.VOIDED = 0 AND /* Main Selection Criteria */
       PMALLGL.PSTGDATE >= {ts '1900-01-01 00:00:00.00'} AND /* Param 1*/
       PMALLGL.PSTGDATE <= {ts '2009-02-23 00:00:00.00'}
 
GROUP BY DISTTYPE
ORDER BY DISTTYPE ASC