If the cybook keeps rebooting, you may have a shot. Mine doesn't get that far--it is stuck on the very first splash page, and doesn't cycle at all. When I push the reset it turns the LED off, but the page is still showing(I know, this is how it's supposed to work) so I can't get off of the page at all. I have tried 'downgrading' but I don't think it gets far enough in the firmware to allow that--nothing happens.
I think a trip back to Bookeen is in the cards---
Anyone know how long it'll take?? Once they contact me, anyway.