Hi, I've had my macbook for 3 years now (1st generation ) and I've had no problem with the USB port until just recently. After the use any USB device (memory stick, phone, external hard drive, etc.) on my macbook, the metal part of the USB cable (the part that was plugged in) becomes extremely hot! I do not know what's causing this but I am suspecting that the resetting of the PRAM and NVRAM couple of weeks ago may have caused it. What exactly is causing this and how can I fix this? Thanks in advance!