One thing no one has mentioned yet is the quality of ATT's signal wherever they are having the disappearing bar issue. Not that it would be the only cause but it may contribute to it. I hope Apple asks those who feel they have the issue to submit their serial numbers so they can get a handle on wether or not it was a bad batch. That would be totally understandable. Real life folks .... they rushed to get 600,000 phones out and if there are a few thousand bad ones out there that would still be less than 1%. The fact that some can replicate the issue and some cannot hints at it , hopefully, not being a design flaw.