I have an iPhone 4S and today I updated to the newest version of iOS (version 8.1.2). After the update I am unable to make a call using the bluetooth. This has never happened before so it leads me to believe there is something in the iOS update that messed up my phone. I have not had time to dig into this to figure out what is going on. I wanted to warn everyone to maybe not be in a big rush to update your phone. When I find out more about this I will provide an update.