We have a 3CX box that has just been installed that is having issues with external calls over ISDN30. Basically when people talk is seems to cut off the first bit of the word when they start talking. An example is below: http://18.104.22.168/20111103120352.wav It happens 5 times in this short clip, I can't really describe it, it's best to listen for yourselves. Internal calls are fine, it's just calls over the ISDN30. What could be causing this? All phones are Snom 821s with the latest firmware. The 3CX software is running on a new HP ML110G6 server with Windows Foundation Server 2008. It has dual SSDs and uses a Sangoma A101 PCI-E card for the ISDN30. The logs for 3CX and the Sangoma show nothing and the phone company have tested the ISDN line and say it's fine.