I found this post from Codybear at XDA but am a little indifferent about how to do it. He says count to ten after disconnecting the usb where for me to get it to work it disconnected it and connected it right back. But you can look at it and see how it works for you... here is the thread, just scroll down to the Table of Contents and select How to Unlock/Flash Rom. Try that and see if it helps anymore in detail.
http://forum.xda-developers.com/show...38#post3680838