Is the kettle loader able to update a record?

I am trying to work around a bug in Kettle's Access connectivity (its losing chinese characters because its not translating the UTF16 used by Access into UTF8).

It turns out that I can keep the chinese if I export from Access into XML and then read from the XML into Kettle. I want to use the OPV Loader to update the label field in the product record so my mapping is as follows:

This appears to work - ie no error messages and the etl_log shows what I would expect (ie the id field contains the ids of the product records that should be updated).  However, if I go and look at the products that should have had their label fields updated, they are unchanged.  If I intentionally screw up the contents of the oIID variable, then the loader reports that it cannot find the product.medication record - just as I would expect.  So its as though it can reference the record but not modify the label field to the the value in ItemLabel.

[Note that its not the end of the world it the OPV Loader will not update a field - I think I can put together the necessary SQL.  However, it would be nice it it could - and it opens up other possibilities like doing price updates.]

Regards, Tim