Okay, I got me a strange one today. One of my collegues, who works from home, tries to call the office with his cell phone. When our box "answers" the call, it is being hung up. He put his sim card in another phone, still causing the hangup. Is he using his landline, he doesn't get hung up, so it also can't be his hands radiating some magical kind of energy causing the hangup. It doesn't matter which inbound route is followed, on all he will get hung up with his cell phone. Other cell phones don't get hung up. Calling him on his cell phone, from inside, can also be done without any problem. I tried enabling and disabling "Send RINGING", to no effect. I'm out of ideas, anyone else got some inspiration? Here's part of the log where it seems to go wrong. My phone rings about half a ring and then displays missed call.