[Freeswitch-users] Early media beginning clipped for certain callers

I have replaced what the incoming caller hears (ringing) with a greeting, instructions, ringing. Works great but for some callers, about 1 second is clipped, it seems to do with who is calling: Caller A cell phone & B land line works every time and is never clipped. Caller C cell phone & D land line clips every time. I added up to a 5 second "sleep" before the media to test but it had no effect telling me the other end is clipping the audio when it starts. Any ideas on what I might try? I can try to lengthen the audio but I didn't want to make the working ones listen to extra silence. Thanks! Mario