It seems that the Epic 4G refuses to work with auxiliary USB ports, possibly cause it's not getting enough power. So make sure to have the Epic 4G USB drivers.
http://org.downloadcenter.samsung.c...bile_Driver_V1.3.800_For_SPH-d700_Epic_4G.zip
Then make sure you plug in the USB cable to a main USB port, not an auxiliary one (depending on your computer, most likely in the rear of the case).
http://org.downloadcenter.samsung.c...bile_Driver_V1.3.800_For_SPH-d700_Epic_4G.zip
Then make sure you plug in the USB cable to a main USB port, not an auxiliary one (depending on your computer, most likely in the rear of the case).