Why can't iCal send out invitees??

Well, nothing has changed, and nothing has been fixed, so here's a restatement of my problem.

I get lost is all the tech talk. However, put simply, here's my simple problem that Apple never figured out either!

Bottom line - as soon as iCloud is introduced into the configuration, my iCal can't send out invites.

When I first got my Macbook pro using my calendar locally I could invite and get acceptances via Apple email using Comcast email address.

As soon as I got the iCloud involved I lost this capability! I messed around for several hours on the phone, got the problem escalated, went to the genius bar and no one ever figured out the solution. So, it hasn't worked for over a year. I bought the mac and it came with Lion. So, my combination where I can't send out invites is Lion and iCloud. It's the CLOUD!!!!

As an experiment I made my calendar local to my mac again (took it away from iCloud), and invites worked!! Unfortunately I got an iPhone and again got corraled into the iCloud. So, my invites don't work again!

My wife has my same configuration except for the fact she doesn't use the iCloud, i.e. her calendar is local. She can send out invites, I can receive them from her, I can accept or decline them and she gets the response.....

Bottom line - as soon as iCloud is introduced into the configuration, my iCal can't send out invites. From what I see out there in the communities, this is a real problem! Apple tech - any solutions?

Anyone out there from Apple care enough to help me out?