Originally Posted by darkcastle
I'm positive. Try this if you don't believe me. Make a call when you are connected to wi-fi using the green 'phone' button in the lower panel. Unplug your wireless router. A message comes up saying 'you are going outside your wi-fi networks range, your call may drop'. The call then drops. There has to be a way to prevent this.
I wasn't going to try it because it makes no sense. Mobile phone networks use the GSM/WCDMA standards and not Wi-Fi. But, just to satisfy myself I did try it and didn't get disconnected with a Wi-Fi error message (as I suspected). The call stayed connected even though the router was unplugged.
I honestly don't know what is going on with your phone and how you are able to make calls over Wi-Fi without using VOIP.
Can I ask who your network carrier is and what country you are in?