Last Friday I received this "Call failed" issue on my phone. Basicly it means that when I have 3G switched on, my phone keeps droping out from calls and gives "Call failed" note regardless if it's in- or outgoing phone call. As soon as I switch off 3G from settings and use only GSM, phone calls are completely fine. I have found some information that this issue is possibly caused by iOS 4.3.3 update and after some research I start to believe that it is so. I live in Finland which is very small country and because of that our service providers really provides us with service (LOL) so when I called my service provider whit this issue they booted 40 3G antennas around me and still my phone keeps doing that, it stoped for a day but started again. So obviously this issue is not with service provider. Now I'm wondering that will iOS 5 fix this issue? Does somebody have more information about this issue?