[CalendarServer-users] User Guids

I've been playing around with trying to change user guids (backed up everything first). I'm doing this as the web access had problems because several of the guids I had were not long enough (assert len > 4). I redid the accounts.xml and the associated calendars/__uids__ and principals/__uids__ directories. The web now access now works fine and sees all calendars in each account, but iCal has lost access to all the calendars that had been defined before (though it still has access to the accounts). Any thoughts on what I've missed? Thanks, Jared