setSelectedRows hides the top row under the header bar
This is finally (after endless experiments) working except that when the grid opens, the top row looks as if it scrolls up under the header bar. There is no scroll bar so you cant get it down to see it (because the grid is longer than the number of records displayed), unless you sort one of the columns. If you just press return you do go into the edit screen of the correct row, so it seems to be working.
I'm using obj.setSelectedRows() to do this.