Story goes like that, I have an old, but working, external HD which used to be connected to my old 2009 MM, it worked fine, I used it as TM backup from both my machines. But I've replaced the old 2009 MM with new 2014 one, and every time I try to connect the HD, it shows the disk for few seconds and disappear back to oblivion. I've changed the USB port, but still nothing. When I connect it back to the 2009, it works fine and other two HD's. Does anyone have any suggestions on how to fix this?