As I received my Raspberry Pi yesterday, today I started to play with it. I installed Raspbmc, but I constantly got
cannot reset port (-110)
error messages. And
ERROR::dwc_otg_hcd_urb_enqueue:477: Not connected
Google search mostly came up with people who had the same problem because they used some devices on the USB ports which the Pi couldn’t power up correctly, so they had to use a hub with its own power source.
Then I finally found a guy with my exact problem: bad USB cable.