Hello everyone, this is my first post! My N10 has been collecting for about 2 years. Actually, it's my wife's. First the charger was lost, then she got an iPod, so she stopped using it. Anyway, I took it out, and just bought the lost accessories again. I bought a charger and an AA battery pack. First, I plugged the battery pack, and added an AA battery I found at home. It wouldn't work. I tried another battery, and it still didn't work. None of them were new anyway, plus I read the note inside the battery pack's cover saying that the player can't run on dry batteries if the built-in battery was empty. So I plugged the charger, and It charged within an hour. That amazed me! When I was charging the MD, I first placed the N10 in the cradle (which I didn't loose!). It charged fine. Then I noticed the AC adapter opening on the battery pack, so I connected the charger through it to test it. It also charged with no problem. So I kept it charging through the battery pack. Within an hour, it was fully charged. I turned the device on and did a quick test. Everything was working fine. I then bought a new AA battery, tried it, and it still wouldn't work! I thought maybe it was because I got a cheap generic AA battery. Today I bought yet another; an Energizer battery this time.. Still not working. What could the problem be? The battery pack wasn't brand new. I bought it from a guy who got the wrong battery pack for his MD player. It looks un-used. Obviously nothing's wrong with the connection, as it charges with no problems. So where's the problem? Is my player too old to run off AA batteries? Is something wrong with my internal-battery? Is this battery pack defected?