Last year I was only using the gumstick batt, and lasted x playback hours. In a trip, I started to use the AA battery for two months. When returning home, my gumstick battery only lasts 60% of x hours... Someone told me that the MD power consumption parameters have been changed (?), and other that the MD charging function is not working properly... can anyone help me? Does the external charger work better? Thanks!, Marco