Oracle Unix 9.2.0.5 on Sun server

[John Pennington]

I have unix test server and production unix server, both are running oracle 9.2.0.5 and both are SUN servers.
On both servers I have a schema that my user is trying to run sql against. It works on the test server but not on the production server. I checked all of the parameters on bother servers - nothing different. I thought it may be a data issue so I exported the schema(user) from production - ftp to the test box / dropped the schema(user) and imported the dmp file. I had expected that the sql would fail but it worked. I'm stumped..The sql is below along with the error message I'm getting on production;
SELECT PartName,PartNo,Model_UH60L,Model_UH60M,Model_HH60 L,Model_HH60M,Model_UH6
0MU,
isnull(DwgNo,'Not Available') as DwgNo,System, NSN,
isnull(NHA_UH60L,'-') as NHA_UH60L,
isnull(NHA_UH60M,'-') as NHA_UH60M,
isnull(NHA_HH60L,'-') as NHA_HH60L,
isnull(NHA_HH60M,'-') as NHA_HH60M,
isnull(NHA_UH60MU,'-') as NHA_UH60MU,
DA2410,FSP,GT5K,Supp5K,AnalystName,AnalystPhone,
isnull(HHeat,'-') as HHeat,isnull(Cold,'-') as Cold,isnull(Humidity,'-') as Humi
dity,isnull(Salt,'-') as Salt,
isnull(Abrasives,'-') as Abrasives,isnull(Fluid,'-') as Fluid,isnull(Fuel,'-') a
s Fuel,
isnull(CurrentMark,'-') as CurrentMark,
isnull(PartAccessIssues,'-') as PartAccessIssues,
isnull(Material,'-') as Material,
isnull(SurfaceRoughness,'-') as SurfaceRoughness,
isnull(FinishType,'-') as FinishType,
isnull(MatWherePartMarked,'-') as MatWherePartMarked,
isnull(Curvature,'-') as Curvature,
isnull(MarkType,'-') as MarkType,
isnull(LabelAttachmentMechanism,'-') as LabelAttachmentMechanism,
isnull(RecPosition,'-') as RecPosition,
isnull(AreaAvailableMark,'-') as AreaAvailableMark,
isnull(LabelType,'-') as LabelType,
isnull(EtchType,'-') as EtchType,
isnull(AirworthyReq,'-') as AirworthyReq,
isnull(NoOfShipSet,'-') as NoOfShipSet, isnull(SerialNo,'-') as SerialNo,
isnull(DataPlateSSNo,'-') as DataPlateSSNo,
isnull (ManuApplication,'-') as ManuApplication,
isnull (NoMarking,'-') as NoMarking
FROM Partmark.Parts WHERE partno='70070-35152-015';

The message I'm getting in production is;
SQL> @test.sql
isnull (NoMarking,'-') as NoMarking
*
ERROR at line 28:
ORA-00904: "ISNULL": invalid identifier

Again both schemas are the same.