I bought three 5V 1A USB chargers (ID: 501)http://www.adafruit.com/products/501
they seemingly work fine on my rasperry pi -- but one won't charge my ipod touch (4th gen): with that one, the ipod won't even acknowledge that it is connected to power at all.
As for the other chargers I got: one of the two other chargers I bought is acknowledged and charges fine with the itouch; the third charger I gave away and don't have immediate access to test.
is this a returnable problem? And if not, should I be worried about using the charger with my RPi?