I opened a ticket, but forgot to give the URL and login.
I'll update the ticket when I get the ticket number in the mail.
Yes, the issue is repeated on your demo site, and I found another issue which I think I read elsewhere in your forums.
Here is what I did:
I added 3 events to your site demo calendar.
Check your demo site for Oct. 2 and 3.
I added the cola drinking for Oct. 2 and check the add more events block. Next I added burping for Oct. 2. Last, I added a birthday for Oct. 3 and logged out.
You can see that the Cola Drink got move to Oct 3. (that's the new issue.)
Now when I log in to the event manager and try to add another event to Oct. 2 or 3, there is no way to do it.