This problem has been happening for approximately a week. When I receive e-mails they are listed on my screen as usual. However, when I go to each '''new''' e-mail with my cursor it 'disappears' (presumably turning white). The e-mail is still there and I can click on where it was. All other e-mails are still visible, and the new e-mail will remain visible once I have read it. Maybe I have clicked on a control switch by mistake ??