C# Winforms: BrightIdeasSoftware.fastObjectListView ButtonClick Event does not fire

Question

I have a FOLV on a form with a button column (IsButton property set to true and ButtonSizing set to CellBounds)

I have attached the event in the designer and can see this under Initialization.

this.fastObjectListView1.ButtonClick += new System.EventHandler
     <BrightIdeasSoftware.CellClickEventArgs>(this.fastObjectListView1_ButtonClick);

And in code behind: -

private void fastObjectListView1_ButtonClick(object sender, CellClickEventArgs e)
{
   Debug.Print("ButtonClick fired");
}

The event does not fire.

Are there other properties required? What could stop the ButtonClick event from firing?