I'm afraid I have to join the recent chorus of those in need of help.
I followed the instructions in "Downgrade" of Post #1. (It seemed to be the right one as I looked at the options.)
After the RUU installation, my Flyer (US Best Buy WiFi model) is stuck at the white screen with HTC. I shut it off, boot into hboot, and all the options but Fastboot take me back to the white screen with HTC. I ran the RUU a second time, and still no dice.
I used the Brightstar 2.27.1540.31 RUU. I've poked around and hoped to be able to figure this out, but alas, I cannot.
My ultimate goal is to install this: http://forum.xda-developers.com/show...6#post25247476
but I need back to GB from HC first.
Thanks, folks! Any and all help is much appreciated.