Either this is a bug or I can't make double click work.
Grid has one column
DblClick code in Grid = Thisform.Release()
Does not work

A post from around May 2002 says try the TextBox double click in the grid.

I Tried putting dblClick code in grid.columns(1).text1.DblClick
This does not seem to work either.

Grid was originally Read Only.

I turned off RO at Grid, Column and Text box.
So the grid is fully user interactive. Still does not work.