A few minutes ago I was surfing the web on my phone and get a text from my friend, asking why I didn't answer his call. A quick review of my "missed calls" shows he tried to call about 2 minutes ago. Yet nothing popped up when he attempted the call. My home wifi signal is fine, and I just tried testing a call from my work phone to my iPhone, call popped up as normal. This has happened several times, usually I'll get a pop up that I have a voicemail, but nothing popped up for the actual call. This is my second iPhone 5, returned the first due to randomly/unexplained drop in HSPA+ signal to EDGE, then right back to HSPA+. New phone has shown similar behavior, went back to the Apple store, was told they had not heard of this issue and because they'd replaced the phone once, there was nothin they could do. Considering just returning the phone and buying a 4s on Craigslist until Apple sorts this mess out.