Thank you for a great plug-in and I love it.
I have upgraded my installation to Premium version, and noticed that in the calendar view, when I hover over any Monday event, the pop up does not show (or only a tiny bit of the right most part of the bubble shows up depending on the theme).
I have a testdrive and you can view it online.
My wordpress version is 3.5 and All in one Event Calendar version is 1.8.3.
The theme at the site is Suffusion. I have buddypress installed and also tested it with Custom Community as well as the buddypress default theme.