To turn off UMA simply go to Options >Mobile Network and set it to Mobile Network Only. This will give you a bold wifi icon (data) and EDGE.
UMA gives you the ability to make voice calls and send/receive sms over your home wireless internet connection. You can browse and get your email with a bold wifi logo and EDGE but your voice calls/sms will go over EDGE.
It sounds like there is an issue with your router/isp if the BB is dropping calls while on UMA. Also, make sure your 911 address is entered in your profile on the TMobile website.
Last edited by John Clark : 02-23-2008 at 11:55 AM.