I have been running Outlook 2007 on a Windows XP machine for quite awhile, with no problems. All of a sudden my setting for "Current View" to "Unread Messages in This Folder" has stopped working. ALL messages remain visible, including both read and unread messages. I have tried rebooting to no avail, as well as having run both Norton and Malwarebytes scans. Any idea what has happened, and how I can fix it?