hi guys rather than using the charger that came with my ipad i plugged my ipad into the mains using my wifes ipod charger which was already out in the side. i was confused to see that my ipad shows "not charging" as if it were plugged into the pcs usb port, as we all know. im confused as both the charger i got with the ipad and my ipod charger both plug into the mains. the non ipad charger is a standard charger for the ipod (generic make not apple). why wont the charger charge the same as the one i got with my ipad?