I have just checked and dual screen is not configured! I'm totally baffled. Thank you all for being so patient with me, and Thanks Pyrochild, using Alt+F4 really helps, at least I don't lose all the work I have done up to the point of using this plugin. It's obviously something to do with my main pc as I also have a laptop running on the XP OS and this plugin works great on there, as it does on my son's laptop which is also Vista Home Premium OS. Maybe my pc, being about 2 years old needs a good service?