I bought the Soundbuds Sport today, and after a few hours of use they have become unusable because when I try to turn them on, they immediately turn off. They are fully charged (the red light turns off when plugged in), so they should be able to be used. However, holding down the power button to turn them on, the light turns blue and they make a rising, beeping tone, immediately followed by a flash of the blue light and a descending beep tone. And then they turn off. Has anybody else had this problem and know how to fix it?