Slightly Complicated Statement works one place not another

[JoeOlliff400]

So, I have the following SQL statement.

 EXEC SQL
     INSERT INTO ENTPART (IRS#,ITEM#,OKAYTOUSE,HTS#1,HTS#2,HTS#3,
     DESC,UNT$,WGTLN,PCLS,PRDCD,COMM1,COMM2,COMM3,COMM4,COMM5,
     COMM6) SELECT DISTINCT (SELECT IRS#CS FROM CUSTHEAD
     where CUS#CS = $S_CUSTF and B287CS = $S_OFFC
     FETCH FIRST ROW ONLY),
     ITEM#,OKAYTOUSE,HTS#1,HTS#2,HTS#3,
     DESC,UNT$,WGTLN,PCLS,PRDCD,COMM1,COMM2,COMM3,COMM4,COMM5,
     COMM6 from ENTPART join CUSTHEAD on IRS#=IRS#CS
     where ITEM#=:ITEM# and HTS#1=:HTS#1 and DESC=ESCR
     and CUS#CS=:CUSNUM and B287CS = :OFFC
     EXCEPT
     SELECT IRS#,ITEM#,OKAYTOUSE,HTS#1,HTS#2,HTS#3,DESC,UNT$,
     WGTLN,PCLS,PRDCD,COMM1,COMM2,COMM3,COMM4,COMM5,COMM6
     from ENTPART join CUSTHEAD on IRS#=IRS#CS
     where CUS#CS = $S_CUSTT and B287CS = $S_OFFC; 

I also have set in the initialization for the SQLRPGLE program this is in Exec SQL set option commit = *none;

SQLCODE is 0 however the copy does not occur in the program. If I use the same statement within STRSQL substituting the variable names with the literals that they hold, it works just fine.

Any ideas?

Thanks