Quit iCal. Open the Calendars folder in ~/Library. (~ represents your home directory)
Select one of the calendar folders (names like 2F42EE3F-854A-4B39-8B64-39B5B7700F6E.calendar) and then select the info.plist in it. Click Preview, and towards the end of the listing you will see
<string>name of calendar</string>
Repeat these steps until you have located the calendar folder for the google calendar. Drag that folder to the Desktop, then restart iCal.
I removed every folder that had anything related to google.com, and I still get this message:
The server did not recognize your user name or password for account “(firstname.lastname@example.org.” Make sure you enter them correctly
Then it crashes again.