[Plugin: FT Calendar] Pop-up box in 'calendar of events' widget is too big

I activated a Calendar of Events widget on my sidebar, and everything works fine- except that when I click on the date on the thumbnail calendar, the box that pops up and shows the list of events for that date is way too big. (See the left sidebar, http://ubcecess.com/) I would like to change the size of that box and make it smaller(at most the size of the widget). Any advice on how I can do this?? Thanks.

http://wordpress.org/extend/plugins/ft-calendar/