"An unexpected error has occurred" - setting up Time Capsule - now happening on 2nd TC

Hi!

I'm sorry if this has been asked a thousand times - I'm brand new to owning an iMac and a TC.

I tried to set my first TC up last week, got through to where it said, "Waiting for AirPort Time Capsule" and every time I would get "An Unexpected Error Has Occured, Please Try Again." Reset it 5 times, did everything again - same response. Called Apple Care, they had me do it another three times, got the same thing. Told me to drive the 50 miles one way to go to the Apple Store to return it. I did that tonight...

Now I have a new TC, and I was assured that it wouldn't happen again. Here I am....with the same error message at the same point in the setup.

I can connect to the internet through the TC on the brand new network I created (every time) - however, my brand new iMac will never configure the TC. I have the TC directly connected from my AT&T Pace Router to the TC by ethernet cable, and the globle on the AirPort Utility is the only thing on there, with the green light for the Internet - it says connected - all of that good stuff. At the bottom, it says, "No configured AirPort base stations have been found..."

I've updated everything I can on my iMac and through the AirPort Utility, so everything is up to date.

Anyone have any clues before I call Apple Care....again and they tell me that this has never happened before? (ugh)

Thanks!