Underpowered USB Port

My brand new macbook has an underpowered USB port. I can only use devices that require very little power, like a thumb drive. My iPod shuffle or my external usb drive show no response on this underpowered port.

I contacted Apple care and they don't I could send it in for repair, but my concern is what "repair" means to them. Given that the USB controller is integrated into the motherboard, I would assume a bad USB port = bad motherboard. I'd rather not have my brand new mac cracked open and have the motherboard swapped out. Do I have any return options?

I bought my macbook at CompUSA (bad idea), and about a week later, I scratched the lid trying to get-off an old apple stick that a friend thought would be a funny joke. CompUSA wouldn't take it back because they said it was damaged.