I found my old powered usb hub yesterday and tried to use it with my 2008 macbook pro to connect my different midi instruments (pad, controller and a keyboard). Unfortunatly, I keep receiving a USB overcurrent error as soon as I plug 1 midi instrument in the powered hub which is connected in the MBP. I've read multiple threads about the USB overcurrent problem and most were fixed by buying a powered hub but I already use a powered hub. The hub seems to be working since the lights are lighting up as soon as I plug it in the wall without being connected in the MBP. Also, all the controllers are working proprely when connected to the MBP itself. It is a 4 slot USB 2.0 hub from APC. Should I buy a new hub ?