I Also still have the problem. At work where now using Trixbox, but at home I have a windows server and Axon is just the right application, very simpel but powerfull. I only have the ring problem with the phone I mentioned above, but not with sipura devices.
Hi, I bought a few days ago a voip hardphone the E-Tech VPPH01. I tested this phone with voipbuster and it works great. When I used Axon there was no ring tone while dialing a extension. It is a long tone instead of a ring ring tone (I hope you understand what I mean) With voipbuster the ringtone works and with asterisk also. But your pbx is much easier so I hope you can look at it ... Kind regards, Martijn