Error adding new itemWarehouseInfo

Question

I am trying to add a new warehouse to selected items via DTW.
The error I am getting is "Update Failed-Feld cannot be updated [ODBC-1029] Application-defined or object-defined error"
Also on some items I am getting "Microsoft SQL Native Client - Violation of PRIMARY KEY constraint 'OITW_PRIMARY_KEY: cannot insert duplicate keys into OITW"
The warehouse is brand new and it DOES NOT EXIST in any of the items ("Auto-Add" is unchecked!)
These are the steps I am performing in DTW:
1. I created 2 files items.csv and itemwarehouseInfo.csv (using templates)
2. In items.csv I added sequential recordKey field (1,2,3,....) and put item codes in the ItemCode column. Overall, I have around 600 items
3. In itemWarehouseInfo.csv I have REcordsKey set to the same numbers as in items.csv (1,2,3...), LineNum is 0 for all lines and WarehouseCode is 113 (the name of the new warehouse I have added in SAP).
4. In DTW, I choose to import oItems, I add items.csv on an item level (header) and itemWarehouseInfo.csv on itemWarehouseInfo level
5. Next, I check to make sure Target Data is correct, then i choose "Update Existing Object" in the Test Mode
i also tried doing an Insert in the test mode, but it also failed. Any ideas?
thanks

Answer 1

I don't think the problem is in the way it's formatted. Like I said, when I view the "Target Data" tab, it is correct, so data is pulled accurately from the files.
The problem is what happens afterwards. I am indeed trying it in test environment.
here's what I am importing
in items.csv
recordKey itemcode
1        10001
(all other fields are blank)
in itemWArehouseInfo I have
REcordKey LineNUm  WarehouseCode
1                0               113