I was having issues with writing back onto my 3tb WD hard drive. It would copy to about 1% then sit for hours. I read a thread somewhere to try a micro USB cable vice the large USB 3 cable. It worked fine, fairly quick, but I'm sure it's not USB full speed 3.0.
Not sure why, but it does work fine with a USB 2.0 cable.
Not sure why, but it does work fine with a USB 2.0 cable.