I have recently started operating digital With a SignaLink USB interface, and I am having intermittent transmit issues. At times when I am transmitting the transmit light on the interface with shutoff and the radio will unkey, also my program, D.M. v4 will freeze up and I have to use task manager to end the program. I suspected that it was RF getting into the interface's circuitry. I changed out my antenna from a ground loop to a dipole which seemed to help but there are still times when it acts this way. Are their any other ways to isolate it from the radio or stray RF, also does anyone have any other explanations as to why this might be occurring.