TESTCASE:

import java.awt.*;

public class test{
    public static final void main(String args[]){
        Frame f = new Frame();
        FileDialog d = new FileDialog(f);
        d.setVisible(true);
    }
}

STEPS TO REPRODUCE:

1. a file dialog opens
2. close the dialog by ESC and the dialog hangs

easily reproducible with GTK file dialogs starting from jdk 7 b100