I'm running into the same thing now. I've tried Doughdaddy's solution, but I seem to be missing something.

I've deleted the CICAL service books, reset the device, reset the DM configuration, configured a new calendar connection in DM, and still no sync. One thing I noted is that even after deleting all my CICAL service books, my calendar is available with all my appointments (it shows as "default" under Options). Should it be completely gone?

Thanks!