[kaidomac]

Make sure you wait until the first one is activated before activating the second one. I had major problems when I activated them back-to-back (5 minutes apart). Also, it can take up to 24 hours to activate unlike the 6 hours they say it will. I had problems with adding my second line (porting both numbers from Verizon), so they had me "replace an existing line" instead of "add a line to my account" when I went through registration with the second one. It's actually kind of confusing because it's not really intuitive, but the AT&T/Apple people are happy to help and get you up and running so if you do have problems it shouldn't last for more than a day or two.