I have a form listview and have used the MouseDown event to launch a
modal dialog if a particular cell is clicked.

This works fine but upon closing the dialog I am left with a dotted
rectangle drawn between where the original click was and where I
clicked to close the dialog.  Until another mouse click occurs this
rectangle resizes as you move the mouse.  I guess this is because the
MouseUp event hasn't fired yet (or fired on the modal dialog).

What is the best way to prevent this, or invoke the MouseUp event once
the dialog has closed.