Migration to SQL 2000 brakes VB COM !

Please help!
Have anyone had a problem switching back end from MS SQL Server 7.0 to 2000? My VB COM object uses RDO_Access class
to save a new record, as a successful result procedure returns new id in the database ("select new_record_id from ResultsTable"). It worked fine on SQL 7, but when testing on SQL 2000 error -2147216503 is returned (automation error).
The actual saving process "exec save_proc_name [parameter list...]" in isql window runs without errors....