Recently while Im working in Outlook's Calendar it has started to go blank, loose all info in my calendar and each time I click on the screen it produces another blank calendar on top of the last one. I open task manager and close out the program. But even when I open task manager I can't see it until I run my mouse over where I think the box is. It then appears and I can close Microsoft Outlook. Once I reopen its fine and nothing is missing. Any ideas?