I apologize beforehand if I'm not abiding by the forum rules, using the wrong category or for simply asking a stupid question. I'm new to the whole SIP system and I've only started to understand everything about it. Right now I'm trying to get my SIP account working on my computer through the use of software (softphone?!). I have tried numerous software and they (almost) all successfully register (I'm using mydivert.com) but none of them 3cx included is able to complete a call. When I call my voicemail I can hear the dial tone and the first few seconds but then the application freezes. I suspect it has something to do with other software running on the system (windows 7) since it also disables the sound on other programs for a small time. Are there any known incompatibility issues that I should know about or any programs that should not run at the same time?! Thanks in advance.