Apple tech support got some info from me Friday as well, but I decided to try a few things this morning.
1. Tried deleting a couple seperate calendars I had with recurring appointments in them, just leaving my main calendar - still error
2. Tried archiving old items up to about the begining of this month - still error
3. Tried running pst repair tool - still error
4. Tried deleting old items up to about the begining of this month - bingo... no DAV config error, however after going through some of the setup and sitting on "downloading contacts from icloud" for about 30 minutes, I just got this error: "Your setup could not be started because of an unexpected error"