When you set the Selected property to select a ListViewItem like this:
this.listView1.Items[0].Selected = true;
you can end up with one item in the list view selected and another one focused. This can cause strange results when trying to use the arrow keys after programmatically selecting a ListViewItem. To avoid this glitch, use this code:
this.listView1.Items[0].Selected = true;
this.listView1.Items[0].Focused = true;