I already did a search on this topic and the general advice was to get a new SIM card from ATT but the problem is I already went through two sim cards in the past month so I am wondering if this is becoming into a hardware problem? I usually get "no sim card error" on my phone once or twice a day, every other day or so. There are times where it doesn't happen for a few days then I get them multiple times in one day (once I got two errors in five minutes). Does this warrant a replacement phone or is there something I'm missing? Not sure how I can approach Apple about this, last time I went they just shrugged it off and said to get a new SIM card.