I have an issue where I put the SIM card in and my phone shows the number of messages I have, so it is connecting to ATT on some level but no bars appear and cannot connect to the network. I tried another SIM, it did not work. But then when I put my SIM card back in all bars popped up, starting working for about a minute or two and then back to the same situation. No bars. Ive been to ATT several times but they seem to know less then I do about it all.
I have the same problem. See this thread. Unfortunately, it seems to be a known N9 hardware problem. If you still have warranty, you should try sending it in to the Nokia Service. They will repair or replace it.
