Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3) We upgraded to two iPhone 4Ss and both have the same problem: About 1 out of 4 outgoing calls do not initiate properly. The display looks like the call is going through (seconds counting, etc.), but the person receiving the call cannot hear or be heard by the caller. The second call usually goes through, but at times a restart is needed in order to make the call. I called AT&T yesterday and was advised to exchange both handsets. Anyone else having this problem?