I am running the WordPress 3.6 and the recently released version of the this calendar event plugin.
When you copy an event or move an event the plugin will revert to 2 hour event length of time and will also sometimes adjust the start time by one hour and only make the event 2 hours from that time.
I am copying an event that is 4 hours long and when I copy it to paste on a different date, it always changes the time of the event back to t a 2 hour period, irregardless of the 4 hour set time that is being copied.
It would be nice if the "copy" button actually copied exactly what is listed and didn't change the times when moving.