Yes, I did everything you said on both my computers (one is a new Imac and the other is a 6 year old MacBook Pro). I was hopeful but in the end what you suggested did not work and after trying to log in with my Apple ID and password (account is verified) I continue to get the message "Could not sign in. Try your network connection and try again."
Since installing Lion and having Face Time, I must have tried it 15 times and I keep getting the same message. I even created 2 other Apple ID accounts with different passwords - I still cannot get in.
A tech support guy at Support Rix suggested going into Library and deleting
com.apple.IC Chatagent.plist I was afraid to do this so I stalled him until his next call to continue this idea. Why do you think he arrived at this idea? He is pretty certain this is what I have to do to get Face Time to work. I did go into Library and there were 5 or so similar .plist files but could not find the one he said above. This guy wanted me to delete all five of the Ichat.plist files and I said no not now.
Anyone know why he wanted me to do this to get this now negative Face Time app to work?