After upgrading to 4.3, I am no longer able to make calls over wifi (a call would dial but immediately end). No problems with calls made over the mobile network though. Does anyone else have this problem?
I looked into settings and discovered that with 4.3, there is now a new option (under wifi and advanced) on auto switching between wifi and mobile network. With this option checked, I can make calls even when wifi is turned on. I suppose what is happening is that the phone is automatically switched to the mobile network when a call cannot be made over wifi.
T-mo needs to get to the bottom of this wifi calling issue under 4.3.