http://support.apple.com/kb/TS1275
seems like it could be your USB or security software causing the issue- which if it is, would be so much better than a hardware problem! good luck
Connect iPhone, iPad, iPod touch or Apple TV (2nd generation) to a different USB port on your Mac or Windows PC. USB 2.0 ports that are built in to the computer are preferred over a hub. If you tried connecting your device to USB ports on the front of the computer, try connecting them to rear USB ports. After doing this, try to restore the device in iTunes.
If the issue continues:
Remove all USB devices except the keyboard, mouse, and your iPhone, iPad, iPod or Apple TV (2nd generation).
Remove all USB hubs and connect your iOS device directly to the computer. If your display has a USB connection, disconnect all USB devices from it.
Connect your device directly to the included USB cable, bypassing the dock.
Restart the computer.
Try to restore the device again in iTunes.
If available, test with alternative, known-good USB cables.
See iPhone, iPad, iPod touch, Apple TV (2nd generation): Troubleshooting USB connection, and this article about a device not being recognized properly by computer when USB drivers are not installed properly or are out of date for additional tips related to USB connections and try to restore again after following those steps.
If the issue persists and you are using a Mac, try resetting the USB connection by following the steps in What to do if your computer won't recognize a FireWire or USB device, and then try restoring the device again. If you are using a Toshiba portable computer, following the steps in this article may resolve the update/restore error.
If the issue persists and you are using virtualization software to run another operating system alongside Mac OS X, quit that software; it may create virtual USB ports that may be causing the issue. Or you can try to control or restrict access to USB ports while running the virtualization software.