Repeating Events add a Day

I’ve just installed this (standard v1.10.9) and am subscribing to my iCloud calendar so I may share it. Almost everything is perfect, except my repeating events (which are showing the correct timing) are having a day added each time. 3 Day events are appearing as 4 days. I can’t find any reference to this, and can’t post on the regular forum, for some reason. Anybody got any ideas?

http://wordpress.org/plugins/all-in-one-event-calendar/