Initial fault when posting on Calendar

Does anyone else have this problem? Since syncing calendars on iCloud, when I first post any event on my calendar and save the event, it seems to save, but then forgets all the detail, and posts as 'New Event 09:00' completely blank. I have to go back in and edit it the second time before it saves the details. This only happens on my Mac, not my iPad which is synced to it.