iCloud not updating when I make changes in iCal on my Mac.

When I start iCal, I receive the message:

"Your calendar couldn't be refreshed.

The URL https://p07-caldav.icloud.com:443/1055473085/principal/ encountered HTTP error 404. Make sure the URL is correct."

Non of my iCal calendars on my mac are being pushed to iCloud. This was all working fine until I added my gmail calendar to share. This wouldn't update and when I unchecked the calendar sync option on gmail profile, my iCal started displaying this message.

Anyone know whats going on?