[MichiganMat]

You're right Shuie, it is universal on a device basis, but not if that device is a gigantic power-hog. This is not a Mac issue, its a limitation of the USB spec, the bus (wires) can only supply so much power to the connected devices. When the device requires more power than the bus can provide (ie harddrive, lamp, etc), the device either needs to be powered externally or, if its in a certain range, can be powered off its own port.

You would have the same problem with that reader if you plugged it into your keyboard attached to a Windows machine.