I followed your advice and wiped everything clean. Nothing on either the Cloud or on iCal or Address Book. I archived my calendar and contacts to a separate folder. Then I did the (now) usual cleaning of the sync history, reauthorizing the computer for sync, permissions repair, restart, etc. Then I sync'd from the Cloud to the Mac (no data to sync, so nothing appeared on the Mac end). Then I manually added one calendar event and one contact on the Mac end and sync'd to the Cloud. Same problem: Nothing appears on the Cloud for contacts or calendar but spinning wheels and server error messages.
So I maintain that the problem is with MobileMe and NOT my setup, which is what all THREE mac geniuses also said. My prospects are now to spend "30 minutes or more" waiting for MobileMe online chat support tomorrow, and the dreary fact that they will probably run me through all the same drills I've already done (over and over again) "one more time."
Frankly, it's no consolation if MobileMe works for other people-- and blaming the customer ("it's your setup" not MobileMe) is standard operating procedure when a company doesn't want to admit they have a serious problem delivering a service that ALL of us paid for. Fact: I paid $100 and MobileMe doesn't work for me, and THREE geniuses said my setup, equipment, etc., are fine. I'm sure I'm not alone in this nightmare. Perhaps there are enough of us "poorly setup" incompetent Mac customers for a class action law suit?
I switched from PCs to Macs years ago because Bill Gates owes me at least a month of my life wasted upgrading Windows, endless app crashes, and GPFs, etc. (Remember upgrading to Windows 95 anyone?) Well, it appears that Apple has finally reached the threshold where they can no longer maintain quality control at the quantity levels their increased market share has given them. Victims of their own success. Disappointing, to say the least.