I got this error while trying to restore in recovery mode this morning, I put the device in actual dfu mode and the restor went through!
To put your device in dfu follow these instructions excatly.
1. Plug your phone into your computer and power it off.
2.Hold the power button for three seconds (until the apple logo comes up)
3. Without releasing the power button hold the home button for ten seconds (3 seconds after the apple logo dissapears.)
4. Continue to hold the home button for 15 seconds (Your computer should start installing usb drivers.)
Then try your restore again!