The faulty cables currently going around would produce the behavior you observe. (as would a damaged 16u2, or a 16u2 that a halfassed clone manufacturer failed to load the firmware onto, which is not unheardof)
The faulty cables currently going around would produce the behavior you observe. (as would a damaged 16u2, or a 16u2 that a halfassed clone manufacturer failed to load the firmware onto, which is not unheardof)