Hi all I have a 27" new model iMac with the wired keyboard that's being a bit odd when my 4s is plugged into the USB port on the keyboard. The machine will often flash up a warning dialogue saying a USB device has drawn too much power, and that the USB ports have been disabled. Sometimes the message will flash up 4 times at once If I unplug the phone and reconnect it again straight away the USB works correctly. Plugging in my iPad or a cf card reader to the same port doesn't give the message so I don't know what to think. Anyone else had random USB issues on new iMac ?