I've tried charging the iPad both ways; through the wall and when connected to my Macbook Pro and when its connect to my MBP its very slow to charge. Last night it was at 40% charge and forty minutes later it was barely at 42%. Of course when hooked up to the wall its a different story... ...but what gives? Side note: How long does it take for the iPad to charge completely? Or even to 80% like all previous iPods?