I'm testing i2004 phones, Model NTDU92, Firmware 0604DCN with a wireless Jabra Headset 9125 and I hear an echo while talking. No echo using the same Jabra headset on an IP 1140 phone, only the IP i2004. We only hear the echo when using the headset, not the handset. Any suggestions or any users out there successfully using a wireless headset w/ a IP i2004 phone and if so, which make and model? I'm hoping to correct the echo using the i2004's with the Jabra model, since that's the headset we currently have in stock. Any suggestions would be greatly appreciated. Thanks in advance.