I'm on an iPhone 4S, running a fresh install of iOS 6 and I'm encountering a weird problem with my APN settings.
Every now and then, about 2 twice a week, I'll be out and about when suddenly my mobile data stops working. When I check my APN settings (apn, username, password), those fields are empty. I enter my details and then I'm back online without further issues.
A couple of days later: same thing happens. I've tried restoring the iOS, wiping and reinstalling but the issue keeps popping up.