This might be slightly off-topic, but … My 8 GB Fuze is 2 years old. I only use it for the FM radio (much better than Sony’s Walkman radio). It had been working about 20 hours before needing a recharge. Suddenly it won’t fully recharge, and dies after 4 or 5 hours. Is this “normal old age” or should the battery still last as long as it did originally?