Over the past few days, when my iPod nano is full after charging, its battery icon shows as just less than full once I unplug the nano. When it is plugged in, it shows the proper plug icon with a full battery. I have "calibrated"' the battery by using it until it shuts off, then completely charging it before use. No luck. Then I did a complete reset to factory settings. That seemed to help at first since the icon showed as full. Then I used it a bit and recharged it again, but now it is back to showing as less than full when the battery is full. Such a weird issue. Anyone have a fix?