Will 3G Microcell work with new Iphone 5?

I was having the same trouble.  Rebooted the microcell and my new phone and that cleared it up.  Not sure if it just happened to be when they brought mine back online.  But it connected immediately upon restart.

I receievd two iPhone 5's today. I set mine up this morning and no Microcell. I called At&T and they said it was an internal server issue and once they got things rolling again my phone would work on 3G microcell. My wife came home later in afternoon so I set her phone up and the microcell works on her phone. This is very perplexing. I compared the setting on both our phones and everything is identical. The only difference is when i activated my phone I did it using autoated system at At&t. when i did the misses phone I spoke with a rep and he activated it.

I got 2 IP5's today as well called ATT etc lots of stories.  This worked.  Go to manage microcell page by logging into your account.  click on disconnect your 3G microcell.  once disconnected, the click add a new MC device. get serial number from bopttom of MC.  and when it re activates your phones will be connected.  worked for both of mine.  took about 35 min to reactivate.  ste says it could take up to 90 min, just like when you first activated the 3G Microcell.

I tried directions from previous poster and it did NOT work for me.  FWIW I activated online.  I also received this lovely error numerous times when I have tried to disconnect and reconnect "S100: We're sorry, but we are experiencing a temporary system error that prevents us from retrieving your account information.
(S100) [CFS|CancelFemtocellService|50000000284] ".  I am logged and and in the section to manage my microcell.

Guess I will try calling customer care tomorrow.  Great stuff ATT!

I can confirm, deactivating your M-Cell and reactivating it is the solution.

Just did that, did NOT have to reboot my iPhone 5, it just came right up to M-Cell

Also, says 4G, this thing must push out the 3.5G signals I guess?

I can confirm this worked for me 2. Deactivated my microcell 3g, waited 10 minutes, reactivated the new one. Showed M-Cell on my iPhone 5 in about 15 minutes.

Mine connects, but only if I turn off LTE. Is this correct, with LTE on it won't automatically recogize the M-Cell and switch to 4G(3G)?

I'm also getting the FTC191: Operation is not allowed at this time. Please try again later. error after disconnecting and trying to reactivate