Currently Being ModeratedMay 5, 2012 8:12 PM (in response to nzavitz)
Force quit iCal. >Force Quit>iCal.
Then remove the com.apple.iCal.plist file from your Macintosh HD/Users/yourusername/Library/Preferences Folder. Drag the .plist file to your desktop.. Also go to your HD/Users/yourusernam/Library/Calendars Folder and remove any files with "Cache" as a part of the file name. Log out/in, or restart and check iCal for functionality.
To find the correct Library Folder for Prefernces/Calendar, select Finder>Go and depress the Option key.Mac OS X (10.7.3), iPad 3G, iPhone 4, 20GB iPod Color, iPod shuffle