xAbre, I just bought the jabra 125 yesterday and I took it home and charged it, took only 1.5 hours to charge. When the blue light goes off the phone is charged. You need to hold the call/ answer button down until you see a solid blue light, it will flash a few times at first but keep holding it down and you should be allright.
If the phone is fully charged the blue light won't go back on when you put it back on the charger.