V nastaveniach - záložka: "Main Monthly Calendar" u položky "ToolTip Type?" máš nastavené čo?
Joomla alebo Overlib???

6.4 Tooltip Type
This allows you to choose what type of tooltip you wish to use. The choices are “Joomla” and
“Overlib”. If you choose “Overlib” this gives more control over the positioning of the toolip but this
can be incompatible with some templates.