if your VoIP provider is broadvoice or vonage (or someone using a similar type of server), their servers goes crazy when our software call polls them during a call and they disconnect the call as a result (our call polls happen every minute, so that is why you get the one minute dropout). You will have to install Axon on your PC and setup your SIP line there and check "Disable call polling" in the Advanced Line Settings". (www.nch.com.au/pbx)