I get the following error in my SQL 2000 database, when trying to update an AS400 table via a linked server:

Server: Msg 7391, Level 16, State 1, Procedure spUploadAllocationTrackHeader, Line 89
[Microsoft][ODBC SQL Server Driver][SQL Server]The operation could not be performed because the OLE DB provider 'MSDASQL' was unable to begin a distributed transaction.


Attempting an update with:
INSERT OPENQUERY(LS_HMVCASW1,
'SELECT
CSIUID, CSIYR, CSICAM, CSISKU, CSIQTY, CSICST, CSIDIS,
CSIRET, CSIRT2, CSIRT3, CSIMRG, CSICAT, CSIART, CSITTL,
CSISUP, CSIREC, CSIFMT, CSIWAS, CSISTS
FROM
WARDOUR1.PCUPDDTA.CASITM
WHERE 1=0') --ADD WHERE 1=0 TO STOP QUERY RETURNING ANY VALUES


SELECT etc....


LS_HMVCASW1 is a linked server using MS OLE DB driver for ODBC databases. The AS/400 table has no keys on the fields and journalling is set on.

Totally baffled by this. Does anyone have any idea what to look into to resove this problem? It was working before...