1- I got a crash from drag drop an item in the calendar from the "all day" section to the calendar. couldn't reproduce it yet.

2- ctrl drag drop creates duplicates but... Deleting the "item" (last option in the deletion dialog) didn't delete all the other duplicates, only the one selected... I.E : Others  didn't disappear even if the item didn't exist anymore.

3- Only way to get rid of the duplicates : choose "Remove item from the  calendar".

 

I guess it's a bug ? Especially that events with no corresponding items displayed in this way havce no properties at all... They are like ghost items.