frecomm

Hey all,
I have a merlin legend 4.0 with mlm. I have one mlx-10 station that has lines assigned. The station can answer the lines when they ring in. It can also place intercom calls. However, when you select a line and go off hook the line light goes out and all you hear is silence in the handset. I verified that the station is unrestricted. I thought I had a bad port, but changed out the 408 card and the problem stayed. I also changed sets and the problem stayed. I also tried copying settings from another functioning station. Anyone experience this before??
Thanks,
Doug