I bought a set of Motorola S9-HD stereo headphones. The charge only lasted a little over an hour. I had been listening to "FlyCast" on my new 9630 Tour. I took them back to the store and they promptly gave me a new set, no questions asked. I now have the same result with my new set of headphones. My understanding is that I should be getting 6 hrs. from a charge. When they shut off I noticed they are quite warm. Does anyone have any ideas why I can't listen longer on a charge? Please help. Thanks.