Duplicate calendar alerts after update to Mavericks
After updating to Mavericks, my Mac Calendar now displays two desktop alerts for every event at the same time. I sync some calendars with Google and some with an Exchange server, and both accounts have the same problem. I can go into preferences and turn off default alerts for each account, but then new events I create on my Mac do not display alerts unless I manually add them. If I turn default alerts on, I get double alerts for all existing events in my calendar as well as all events created on my phone or other interfaces. The double alerts look like this:
I didn't have this problem under Mountain Lion -- is there a way to get it to stop duplicating alerts but still have a default 15 minute alert for new events?
MacBook Air (13-INCH, MID 2011), Mac OS X (10.6.6)