I suspect from all the reviews that the real culprit is quality control from the mfg. side. My h700 stopped working within the month. It would receive but not transmit. Suspect flip mike problems. Motorola is providing new one. Unfortuneately this is like being in the lottery. Will I win or not. Will find out if replacement h700 works. The vendor was also poor. I called 10 days after their one month warranty (total Joke) and they said so sorry contact motorola. You are gambling when you purchase this product.