iCal crashing every 2-3 days on MBP

Every 2-3 days iCal crashes. It always happens during new event entry, usually when I'm trying to edit the date and/or time. The entry suddenly stops, the ball spins, it lasts for 20-30 seconds, then it shuts down iCal and says "iCal unexpectedly quit". It happens roughly every 5-10 times I enter a new event into the calendar.

I have iCal configured with one primary G Cal, plus the "holidays" and "birthdays" calendars.

I've taken it to the Genius bar; they deleted my calendar file, and it didn't help. It happened consistently in Snow Leopard, Lion, and Mountain Lion. I upgraded to Maverick and it hasn't cured the problem either.

Any advice? Stumped.

--jw