Windows live mail calendar

I can't add any events to the Windows live mail calendar any more, either through the quick entry box at the bottom right or through the calendar function on the bottom left. All calendar dates entered so far are displayed and I can enter text in the quick entry box but it does not transfer to the calendar. On opening the calendar function on the left, all dates are displayed but no new entry is possible. Could this have something to do with having registered for Windows live mail on my mobile. When I open my mail account on my desktop now it asks me to log in to windows live mail, but whether I do or not makes no difference.