[Plugin: Ajax Event Calendar] Problems with CSS and lines height

Hi everyone,

I made some changes in custom.css but the is only one last thing that I can’t resolve. Here is my calendar: http://www.allcityblog.fr/agenda/.
I don’t understant why some events are one line, and others take two lines. For the event that are in turquoise, it looks weird.

Can you help to change the height of the lines or to edit my CSS in order to have the same color on the 2 lines?

Thank you very much in advance.

http://wordpress.org/extend/plugins/ajax-event-calendar/