Hi Folks, I have download 3cx free version - 6.1.0 on w2008, linksys spa942, and grandstream 4104 (v1.0.08) for FXO to PSTN. I'll do the upgrade once I have proof of concept working. Outbound calling works no problem. Calls between extensions seems to work fine. On PSTN In bound calling - my wife says I sound like Darth Vader with the sound of a light saber whirring in the background. On the IP phone - the PSTN in bound caller sounds fine, however, the PSTN caller hears a remake of star wars. Any ideas? Thanks in advance Dean.