I found the problem...

I was hiding the columns in the Init() method, BEFORE the RecordSource was set, so when the RecordSource was then set later, it was still filling the next non-visible column.

Here is the working code:

   With thisform.containerJobItems.gridResults
     .recordsource=lcJobListAlias
     .set_header_captions()   
     .column8.visible=.f.
     .column9.visible=.f.
     .column10.visible=.f.
   Endwith

>Have you reorder the columns ?
>
>On this case you cannot use columnIndex:
>
>

>Grid.ColumnName.Visible = .F.
>....
>
>* or
>FOR EACH cl IN grid.columns
>  IF INLIST(m.cl.ColumnOrder,8,9,10)
>      cl.Visible = .F.
>      EXIT
>  ENDIF
>NEXT
>