I just got it in the mail yesterday and I've been using it non-stop (except for sleep and going to work). I think there is something wrong with it. One of the USB ports doesn't seem to work. Not only that but it looks like tiny sparks start appearing as the usb touches the port. I know this is not normal. I should contact Apple and get mine replaced? Can I do this at the store? Edit: Ok, I think I know what it is. It doesn't appear to be the iMac but the usb cable that came with the bluray drive I bought.