At least two people have reported that while they have events in their calendar, the monthly view does not show them as it should. Now, while I am fairly confident that this is not a bug but something else, nevertheless I 'd like to help resolve the problem.
I have seen screenshots of what you are describing, but that's not much use in solving the issue. So, can someone post or mail me the HTML source of these pages where you don't see the events in the calendar? You should accompany the HTML with a brief description of where and what you were expecting to see but don't.