hello mr tele-tech, can u help me with the ns300 it seems even i convert to ulaw and trimmed name on my ns300, it only loads no error prompt and after it loads there is no transfer file success is there anyway i can transfer my .wav to the kx-ns300bx. I also just added sd card it seems there is no sd card but still the same error. Is there anyway u can help me ? I want to retrieve the old way of telephone system